Category Archives for "SCUBA Diving Lessons"

Your RMV Rate, How To Calculate And Use It To Be A Better Diver!

By Jose Cernuda

How much gas did you have left after your last dive? Do you know the precise number as a volume? Do you know how much your average consumption rate is? While It’s extremely common for divers to ask each other how much gas they had left after a dive many people express what was left in terms of PSI or BAR. And while that’s helpful if both you and your buddy were using the same tank it becomes tricky if you’re using different cylinders.

The most precise way to know is using your RMV. If you are serious about diving and improving your diving then you need to know this number. There is a famous business quote from Peter Drucker “If you can’t measure it, you can’t manage it”. This is certainly true of your breathing rate. If you’ve ever wondered about how to measure, use and calculate your breathing rate you’re going to want to read on.

What is RMV?

RMV stands for Respiratory Minute Volume. It is a way divers express how much gas was consumed during a dive. RMV is always expressed as a volume. In the Imperial system, we use cubic feet per minute to express RMV. In the Metric system, RMV is expressed in Liters per minute. RMV is usually standardized as a measurement on the surface. This means that if, for example, you have an RMV of 1 cubic foot per minute  (28 liters per minute) on the surface you’ll use 2 cubic feet (56 liters) at 33 feet (10 meters), 3 cubic feet (84 liters) at 66 feet (20 meters), etc.. because of Boyles Law and the increase in atmospheric pressure. The illustration below shows how the increase in depth/pressure also affects your breathing rate.

Depth Chart w Lungs 1

By knowing the amount of gas you consume on a dive you will know:

  • If you consumed more or less than on your average dive
  • If your breathing rate is getting better or worse
  • How much gas you need to do a particular dive
  • What tank capacity is best suited for you

RMV Vs. SAC

SAC stands for Surface Air Consumption (rate). Many divers use the terms RMV and SAC interchangeably. Strictly speaking, however, SAC is supposed to be measured in PSI per minute or BAR per minute. Because it is a measurement of pressure, SAC is specific to the tank that it was measured on. This means your SAC rate will be different when you use a different-sized tank. We did a separate article on SAC rates here if you are interested in delving into this topic.

The important thing to understand is that If you look at the online calculators, apps that are available for smartphones, and even the software used for dive computers you’ll see that it’s difficult to get a consensus on whether SAC should always be measured as a pressure or a volume. RMV however, is always measured as a volume. For this reason, RMV is the unit of measurement I like to use when teaching how to measure your breathing rate. If you are unsure, just keep reading on. RMV is probably the better choice.

Ultimately, It doesn’t matter if you measure your breathing rate as cubic feet per minute, liters per minute, BAR per minute, or PSI per minute as long as you understand what you are measuring and how to use your measurements. There are many online debates about this very topic, but for our purposes, we’ll treat RMV as a volume and SAC as a measurement of pressure.

RMV Calculator

Now that you understand what RMV is, let’s look at what you need to measure to figure out your surface Respiratory Minute Volume. Because the information you need is slightly different in the imperial system than it is in the metric system, we’ll go over both below.

Imperial System

To figure out your RMV you’ll need to know the capacity of the tank you used for a given dive as well as its service pressure. You’ll then go on a dive and for a minimum of 10 minutes (longer is better) and make a note of your average depth, your starting and ending pressure in PSI during your timed RMV test and the amount of time you ran your test for. We’ll give you tips later in this article on best practices for getting these numbers, but for now, you just need to know the information you’ll need to collect. With these numbers on hand, you can plug them into the calculator below to get your surface RMV.

RMV Calculator (Imperial)

Metric System

To figure out your RMV in the metric system you’ll need to know the capacity of the tank you used for a given dive. Then you’ll then go on a dive and for a minimum of 10 minutes (longer is better) and make a take note of your average depth, your starting and ending pressure in BAR during your timed RMV test, and the amount of time you ran your test for. We’ll give you tips later in this article on best practices for getting these numbers, but for now, you just need to know the information you’ll need to collect. With these numbers on hand, you can plug them into the calculator below to get your surface RMV.

RMV Calculator (Metric)

Best Practices for Measuring Your RMV

To get the most accurate RMV possible you’ll want to follow the following 3 tips”

  • Pick a dive where you won’t be exerting yourself excessively because of currents or any other conditions.
  • Use a slate to write down all your information
  • Pick a dive where your depth will be relatively constant.

With your slate ready, and calm dive where you’ll maintain a relatively constant depth you’ll be ready to begin your RMV test.

Once you’ve descended and ready to begin measuring, you’ll take a look at your submersible pressure gauge (SPG) and write down your pressure in PSI or BAR. You’ll also want to make a note of the time. Then simply go about your dive as usual. You’ll want to measure for at least 10 minutes (the longer the better). After 10 or more minutes have elapsed make a note of how much gas is left as measured by your SPG and also how long you were diving for. You’ll also need to make a note of average depth during the test. With these numbers handy you can now calculate your RMV either manually or using the online RMV calculator.

What is a good RMV?

A lot of factors go into determining your RMV rate. The single biggest factor is probably your body size. Below is a chart with average RMV rates for an experienced diver using an Aluminum 80 (11.2 liter) tank. This is for a dive where the diver is not exerting themselves and in tropical waters. It is only a guide to get a rough idea of where your RMV could be. You may be higher or lower than what’s listed on the table.

  • Imperial

  • Metric

Under 140140-180180-220220 Plus
0.4 Cu. Ft. per minute0.5 Cu. Ft. per minute0.6 Cu. Ft. per minute0.7 Cu. Ft. per minute

What Affects your RMV Rate?

Many factors influence the rate at which you consume gas from your SCUBA tank. Some of those factors include:

  • Your physical size: The larger you are the larger your lungs are and the more gas you will consume as you dive.
  • Your exertion level throughout the dive: Swimming fast or against a current are examples of things that will cause you to use more gas.
  • Your buoyancy and trim throughout the dive: If your buoyancy is off or you’re not properly trimmed out in the water, you will likely exert yourself more and consume more gas throughout the dive.
  • Water Temperature: If you do not have proper thermal protection, your body may begin to shiver and you’ll consume more gas as a consequence of your body trying to stay warm.
  • Mental State / Anxiety: If you are anxious, nervous, or not confident in your diving ability this increased anxiousness will often cause you to breathe faster
  • Your level of physical fitness: The more cardiovascularly fit you are the more efficient your breathing will be. If you become winded from climbing a flight of stairs, you’ll also likely consume more gas while diving than someone who regularly runs marathons.

How Can I Decrease My SAC Rate?

A good RMV rate is part of being a great diver! There are many things you can do to improve your RMV rate. Many of these suggestions are topics on to themselves and we even have an entire course, much of which is devoted to helping you achieve a lower RMV rate. Below are the top 4 things you can do to decrease your RMV rate.

Master your Buoyancy

If you are struggling to stay down because you don’t have enough ballast or have too much ballast and are kicking just to stay off the bottom, then you are surely wasting energy and driving your RMV rate up. Doing a proper buoyancy check, learning where your dump valves are, and mastering buoyancy are the first steps toward a lower RMV rate.

Learn How to Trim Your Body Out properly. 

If you are not trimmed out properly in the water, you’ll consume more energy throughout the dive. Notice in the illustration below how the diver to the left encounters more resistance as she tries to kick. This is because she isn’t trimmed out efficiently.

Streamlined Diver Vs. Non Streamlined

Use the Frog Kick or the Modified Frog Kick More

The frog kick and the modified frog kick require less energy than the flutter kick when you are diving. Because these kicks have a resting phase built-in you end up kicking less to cover the same distance underwater. Mastering the frog kick and the modified frog kick is one of the things you can do to help to lower your breathing rate.

Frog kick sm
frog kick modified sm

Become Comfortable Underwater

Your mental state plays a larger role in your breathing rate than most people realize. If you are not completely comfortable underwater it’s likely that your heightened state of anxiety will also raise your breathing rate. Being comfortable with all the basics of SCUBA diving including mask removal and replacement and buddy breathing, in case of emergency, are just the beginning.

Using Your RMV to Estimate the Gas Needed For A Dive

Once you know what your RMV, you can use it to estimate the amount of gas you’ll need at depth. Remember that in salt water you’ll encounter an additional atmosphere of pressure every 33 feet (10 meters. Because of this, the deeper you go the more gas you’ll consume. You can use the calculator below to estimate how much gas you’ll need at a given depth and time.

  • Imperial

  • Metric

Using Your RMV To Choose A SCUBA Cylinder

Similar to estimating the gas you’ll need for a dive you can also use your RMV to help you choose the best SCUBA tank for given dive. There are a couple of things you need to keep in mind when doing this. First, remember that you always need to leave an amount of gas in the tank for emergencies. You never want to completely drain a SCUBA tank. Second, if you are purchasing a tank, you want to purchase one that you can use for the deepest dives you plan to do.

With this in mind, you can look at a dive table to determine what the no-decompression limit is for the depth you plan to dive to. From here, knowing your RMV you can determine the amount of gas you’d need to complete the dive. Add in your reserve gas and you should have a good idea of the capacity of the tank that you need. There’s a bit more to choosing a tank, but at least you have an idea of the capacity of the cylinder you should get. For more information on choosing the best SCUBA tank for you check out this article.

Calculating Your RMV Manually

Imperial System

To manually calculate your RMV you’ll need to know the capacity and working pressure of the cylinder you used during your RMV test. You’ll also need to know your starting PSI, your ending PSI, your average depth, and the time you did the test for.

Step 1: Calculate your “Tank Factor”. The “Tank Factor” is a name given to the value in cubic feet that 1 PSI represents. Calculating your tank factor is simple. Just divide the capacity of the tank by its service pressure. So, as an example, if you are using aluminum 80 for the test. You can look at the tank's specifications (LINK) and determine that an aluminum 80 has 77.4 cubic feet when filled to 3000 PSI. That means that the tank factor is (77.4 / 3000) = .0258.

Step 2: Determine how much gas was used during the test in cubic feet. Let’s assume during your RMV test you started with 2700 PSI and ended the test with 1900 PSI. This means you consumed 800 PSI during the test (2700 PSI – 1900 PSI) = 800 PSI. You need to convert 800 PSI to cubic feet, so now you’ll multiply the PSI consumed by the tank factor found in step 1. So (800 * .0258) = 20.64 Cubic Feet.

Step 3: Calculate your depth in Atmospheres Absolute. RMV is expressed at the surface. This means you need to account for the atmospheric pressure and how it compresses the gas you breathe underwater. Let’s assume you did your test at an average depth of 50 feet. To convert 50 feet to ATA you’ll divide it by 33 and then add 1. This is assuming your dive was in saltwater. For freshwater, you would divide by 34 and add 1. This is because salt water is slightly denser than freshwater. So ((50/33)+1) = 2.515 Atmospheres absolute.

Step 4: Divide the total gas in cubic feet by your ATA. So (20.64 / 2.515) = 8.2 Cubic Feet.

Step 5: Divide your result from step 4 by the total amount of time the test was conducted for. Let’s assume we ran our test for 15 minutes. This means (8.2 / 15) = .547.

For this test, the average RMV is .547. We can round this up to .55. This means the diver breathes about .55 cubic feet each minute on the surface.

Metric System

To manually calculate your RMV you’ll need to know the capacity of the cylinder you used during your RMV test. You’ll also need to know your starting BAR, your ending BAR, your average depth, and the time you did the test for.

Step 1: Determine how much gas was used during the test in Liters. Let’s assume you completed your RMV test with an 11.1-liter tank. During your RMV test, you started with 180 BAR and ended the test with 110 BAR. This means you consumed 70 BAR during the test (180 BAR – 110 BAR) = 70 BAR. You need to convert 70 BAR to liters, so now you’ll multiply the BAR consumed by the capacity of the cylinder. So (11.1 * 60) = 777. This means you consumed 777 liters of gas during the test

Step 2: Calculate your depth in Atmospheres Absolute. RMV is expressed at the surface. This means you need to account for the atmospheric pressure and how it compresses the gas you breathe underwater. Let’s assume you did your test at an average depth of 15 meters. To convert 15 meters to ATA you’ll divide it by 10 and then add 1. So ((15/10)+1) = 2.5 Atmospheres absolute.

Step 3: Divide the total gas in liters by your ATA. So (777 / 2.5) = 310.8 liters. This is the amount of gas you consumed when adjusted for atmospheric pressure.

Step 4: Divide your result from step 3 by the total amount of time the test was conducted for. Let’s assume we ran our test for 20 minutes. This means (310.8 / 20) = 15.54.

For this test, the average RMV is .15.54 liters per minute. We can round this up to 15.5. This means the diver breathes about 15.5 liters each minute on the surface.

Knowing your RMV rate, how to calculate it and how to use it is one of the most powerful tools you can have in your diving arsenal. What’s your RMV rate and how do you use it? Let us know in the comments below.

Your SAC Rate, Why It’s Important, and Why You Need To Know How To Calculate It!

By Jose Cernuda

One of the main things that separate experienced and efficient divers from novices is the amount of gas they consume during a dive. Efficient divers will use less gas than someone new and still learning to SCUBA dive. It’s not uncommon as a beginning diver to come back to the boat with just your reserve pressure while your instructor still has their tank half full.  So, how can you measure the amount of gas being consumed by a diver? This is where your SAC rate comes in.

What is SAC Rate?

Surface Air Consumption (SAC) rate is a measurement used to express how much gas a diver uses while diving. In the imperial system, it is measured in pounds per square inch (PSI) per minute. In the metric system, we measure surface air consumption in BAR per minute. It’s extremely important to understand that the measurement is expressed at the surface. Because atmospheric pressure increases as we dive deeper, the deeper we go, the more gas we consume.

This means that a diver who, for example, breathes 30 PSI per minute on the surface will use 60 PSI at 33 feet (10 meters) and 90 PSI at 66 feet (20 meters). As you can see from the image below, the deeper you go the more gas you will consume. 

Depth Chart w Lungs 1

SAC Rate Calculator

To figure out your SAC rate you’ll need your average depth for a dive, the time you dived for, the amount of gas you observed was used on your submersible pressure gauge (SPG) in PSI or BAR, and the tank you are using during the dive. 

Below is a SAC rate calculator. To understand how the math behind how the SAC rate is calculated, the best practices for getting these numbers, and how you can use your SAC rate read on.

  • Imperial

  • Metric

Why is SAC Rate Important? 

Knowing your SAC rate is important for several reasons, you can use it to:

  • Estimate how much gas will be needed for a given dive
  • Choose the correct sized tank for a dive
  • Track your progress as a diver to see how you improve from dive to dive
  • In Technical diving use it to calculate the amount of gas needed for decompression and in case of emergencies

Dive Computers and your SAC Rate

You can calculate your SAC rate manually, by using a calculator like the one on this page, or you can also get your SAC rate from many dive computers. If your dive computer is air integrated there is a good chance that your dive computer calculates your SAC rate for you.

Even if your dive computer isn’t air integrated, there’s a chance the app or software that connects to your computer can calculate your SAC rate for you.

Because information about your dives is stored by the dive computer, all you need to do is enter the information about the cylinder you used for the dive, your starting pressure, and your ending pressure to have the software calculate your SAC rate.

An important distinction is that not all dive computers / Instructors / textbooks use the term SAC rate. Some call your breathing rate your Respiratory Minute Volume (RMV) or even Surface Consumption Rate (SCR). All these terms are used universally by divers to measure and keep track of your breathing rate on the surface.

What is RMV in SCUBA Diving? 

Respiratory Minute Volume (RMV) is the amount of gas that a diver consumes during a dive expressed as a volume. The measurement is expressed as on the surface. In the imperial system, we use Cubic Feet per Minute to express our RMV. In The metric system, we use Liters Per Minute.

RMV VS. SAC What’s the difference?

In the diving community the terms Surface Air Consumption (SAC) rate and Respiratory Minute Volume (RMV) rate, are often used interchangeably. Even though the difference is that SAC is expressed as PSI per minute (imperial) or BAR per minute (Metric). While RMV is expressed as a volume (cubic feet per minute or liters per minute).

The problem with using the SAC rate in diving is that the number is dependent on the cylinder being used. So, if for example, you go from using an Aluminum 80 on one dive to a low-pressure steel 95 on a different dive, the SAC rate you calculated using the aluminum 80 won’t be accurate now that you switched tanks. When you standardize the number to RMV the number stays the same no matter what tank you dive with.

I personally teach how to calculate RMV in my SCUBA classes and bypass the entire discussion of SAC rate because it’s a universal number that doesn’t change based on the tank you are using.

Because SAC and RMV are used interchangeably by many, you may find SAC calculators both online, inside of apps, and by dive computers that express the breathing rate as a volume (cubic feet per minute or liters per minute). There is much discussion on internet forums about this topic. The important thing is to understand is what the numbers mean and if you are diving with a buddy and you are comparing numbers to make sure you both are using the same unit of measurement. The semantics about whether SAC should be expressed as pressure or as a volume is really irrelevant when you understand the math and how to use it. 

RMV Calculator

Using the RMV calculator below you can see how you get a value that represents volume instead of PSI or BAR. This value is more useful since the volume of gas that you breathe remains constant with different tanks.

  • Imperial

  • Metric

SAC Rate to RMV Calculator

If you already know your SAC rate and the tank you used when you calculated it. You can use the SAC rate to RMV calculator below to convert your SAC rate to RMV. This calculator takes your PSI per minute and converts it to Cubic feet per minute in the imperial system. In the metric calculator it converts BAR per minute to Liters per minute. 

  • Imperial

  • Metric

Best Practices for Measuring Your SAC or RMV

Regardless of whether you use SAC or RMV to measure your breathing rate, the process of measuring it is the same. You’ll want to pick a dive where you won’t be exerting yourself excessively because of currents or any other conditions. You’ll also want to pick a dive where your depth will be relatively constant. Once you’ve descended and ready to begin measuring, you’ll take a look at your submersible pressure gauge (SPG) and write down your pressure in PSI or BAR. You’ll also want to make a note of the time. Then simply go about your dive as usual. You’ll want to measure for at least 10 minutes (the longer the better). After 10 or more minutes have elapsed make a note of how much gas is left as measured by your SPG and also how long you were diving for. You’ll also need to make a note of average depth during the test. With these numbers handy you can now calculate your SAC or RMV either manually or using the online calculator.

Your SAC/RMV at Depth

Once you know what your SAC / RMV is, you can use it to estimate the amount of gas you’ll need at depth. Remember that in saltwater you’ll encounter an additional atmosphere of pressure every 33 feet (10 meters). Using the calculator below you can estimate how much gas you’ll use for a given dive. It's important to understand that the calculator below only calculates how much gas you will consume. You also need to factor in your reserve gas in case of an emergency!

  • Imperial

  • Metric

What Affects your SAC Rate / RMV Rate?

Many factors influence the rate at which you consume gas from your SCUBA tank. Some of those factors include:

  • Your physical size: The larger you are the larger your lungs are and the more gas you will consume as you dive.
  • Your exertion level throughout the dive: Swimming fast or against a current are examples of things that will cause you to use more gas.
  • Your buoyancy and trim throughout the dive: If your buoyancy is off or you’re not properly trimmed out in the water, you will likely exert yourself more and consume more gas throughout the dive.
  • Water Temperature: If you do not have proper thermal protection, your body may begin to shiver and you’ll consume more gas as a consequence of your body trying to stay warm.
  • Mental State / Anxiety: If you are anxious, nervous, or not confident in your diving ability this increased anxiousness will often cause you to breathe faster
  • Your level of physical fitness: The more cardiovascularly fit you are the more efficient your breathing will be. If you become winded from climbing a flight of stairs, you’ll also likely consume more gas while diving than someone who regularly runs marathons.

What Is A Good SAC Rate?

A lot of factors go into determining your SAC rate. The single biggest factor is probably your body size. Below is a chart with average SAC / RMV rates for an experienced diver using an Aluminum 80 (Aluminum 11.2 liter) tank. This is for a dive where the diver is not exerting themselves, in tropical waters using a single tank. It is only a guide to get a rough idea of where your SAC / RMV could be. You may be higher or lower than what’s listed on the table. The important thing is to do the measurement and know your measurement. Once you have a starting point you can work on improving your SAC rate. 

  • Imperial

  • Metric

RMV / SAC Rates by Diver in Pounds

Under 140140-180180-220220 Plus
0.4 Cu. Ft. per minute0.5 Cu. Ft. per minute0.6 Cu. Ft. per minute0.7 Cu. Ft. per minute
16 PSI per minute20 PSI per minute24 PSI per minute28 PSI per minute

How Can I Decrease My SAC Rate?

A good SAC rate is part of being a great diver! There are many things you can do to improve your SAC rate. Many of these suggestions are topics on to themselves and we even have an entire course, much of which is devoted to helping you achieve a lower SAC rate. Below are the top 4 things you can do to decrease your SAC rate.

Master your Buoyancy

If you are struggling to stay down because you don’t have enough ballast or have too much ballast and are kicking just to stay off the bottom, then you are surely wasting energy and driving your SAC rate up. Doing a proper buoyancy check, learning where your dump valves are, and mastering buoyancy are the first steps toward a lower SAC rate.

Learn how to trim your body out properly. 

If you are not trimmed out properly in the water, you’ll consume more energy throughout the dive. Notice in the illustration below how the diver to the left encounters more resistance as she tries to kick. This is because she isn’t trimmed out efficiently.

Streamlined Diver Vs. Non Streamlined

Use the frog kick or modified frog kick more

The frog kick and the modified frog kick require less energy than the flutter kick when you are diving. Because these kicks have a resting phase built-in you end up kicking less to cover the same distance underwater. Mastering the frog kick and the modified frog kick are one of the things you can do to help to lower your breathing rate.

Frog kick sm
frog kick modified sm

Become More Comfortable Underwater

Your mental state plays a larger role in your breathing rate than most people realize. If you are not completely comfortable underwater it’s likely that your heightened state of anxiety will also raise your breathing rate. Being comfortable with all the basics of SCUBA diving including mask removal and replacement and buddy breathing, in case of emergency, are just the beginning. As you gain experience and become completely comfortable with being underwater your breathing rate will become lower. 

How To Calculate SAC Rate (Formula)

You might be wondering, how are the numbers given by the calculators computed? Below is the explanation so you can understand the math and how the SAC rate works.

Imperial System SAC Rate Calculation

Computing your SAC rate is fairly straight forward. Remember to follow the guidelines in this article best practices for calculating your SAC / RMV. You can calculate your SAC rate in 3 easy steps. To do so, you’ll need the following:

  • Average depth during the test
  • Starting and ending PSI during the test
  • The amount of time you conducted your SAC rate test for

Let’s assume the following variables for our example:

  • Depth = 55 Feet (Saltwater)
  • Starting PSI = 2700, Ending PSI = 1800
  • Time of Test = 15 minutes

Step 1: Figure out your depth in atmospheres absolute. In this example we assume a dive in saltwater, so we use 33 feet as an atmosphere. If you are diving in freshwater, you’d use 34 feet to calculate an atmosphere. To figure out your depth in atmospheres absolute (ATA) divide your depth by 33 and add 1 to it. So, if for example, you dived to 55 feet, you’ll divide 55 by 33 and add 1. So (55/33) + 1 = 2.68. 2.68 = Your depth in atmospheres absolute (ATA)

Step 2: Figure out how much gas you used in PSI. Assuming you started your test with 2700 PSI and you ended up with 1800 PSI, it means you consumed 900 PSI during your test. 2700 PSI-1800 PSI= 900 PSI.

Step 3: Divide the total PSI used by your ATA and then by the total number of minutes you did the test for. So (900/2.68 = 335.82) and (335.82/15 = 22.38). This gives you your SAC rate. So your SAC rate for this example is 22.38 PSI per minute.

The Formula for calculating your SAC rate is.

((Starting PSI – Ending PSI) / Depth in ATA) / Duration of test) = SAC Rate

*Remember that your SAC rate is dependent on the cylinder you used. Your SAC rate will be different if you use a different cylinder.

Metric System SAC Rate Calculation

Computing your SAC rate is fairly straight forward in the metric system. Remember to follow the guidelines in this article best practices for calculating your SAC / RMV. You can calculate your SAC rate in 3 easy steps. To do so, you’ll need the following:

  • Average depth during the test
  • Starting and ending BAR during the test
  • The amount of time you conducted your SAC rate test for

Let’s assume the following variables for our example:

  • Depth = 17 Meters (Saltwater)
  • Starting pressure in BAR = 190, Ending pressure in BAR = 120
  • Time of Test = 15 minutes

Step 1: Figure out your depth in atmospheres absolute. To figure out your depth in atmospheres absolute (ATA) divide your depth by 17 Meters By 10 and add 1 to it. So, if for example, you dived to 17 meters, you’ll divide 17 by 10 and add 1. So (17/10) + 1 = 2.7. 2.7 = Your depth in atmospheres absolute (ATA)

Step 2: Figure out how much gas you used in PSI. Assuming you started your test with 190 BAR and you ended up with 120 BAR, it means you consumed 70 BAR during your test. 190 BAR -120 BAR = 70 BAR.

Step 3: Divide the total pressure in BAR you used by your ATA and then by the total number of minutes you did the test for. So (70/2.7 = 25.92) and (25.92/15 = 1.72). This gives you your SAC rate. So, your SAC rate for this example is 1.72 BAR per minute.

The Formula for calculating your SAC rate is.

((Starting BAR – Ending BAR) / Depth in ATA) / Duration of test) = SAC Rate

*Remember that your SAC rate is dependent on the cylinder you used. Your SAC rate will be different if you use a different cylinder.

Do you know your SAC Rate? How do you plan to calculate and use this number? Let us know in the comments below.

How to Find The Perfect Dive Buddy and Use the Buddy System So That Your Next Dive Will Be Amazing

By Jose Cernuda

Two SCUBA Buddies Gearing Up

Every experienced diver knows buddy diving is about much more than just pairing up with another certified diver on the boat.

A bad dive buddy will ruin what would otherwise have been an amazing dive. They can even put you into a stressful or even dangerous situation.

Choosing a dive buddy is one of the most important things you need to do to have fun and safe dives.

So, if you’ve ever wondered how to find and choose a great dive buddy, or how you can use the buddy system so that you are a great buddy yourself, then you’ll want to read on.

What is a dive buddy?

In SCUBA diving, one of the first things that you learn is that you always dive with a buddy. The purpose of the dive buddy is to increase your safety throughout the dive.

The idea is that by having a competent dive buddy with you that person in essence acts as a safety diver for you, and you in turn act as a safety diver for them.

By having two competent divers pair up you now have a redundant gas supply as well as an additional set of eyes, ears, and even a second brain to process what is happening and make good decisions underwater.

Your dive buddy is the person you dive with that provides redundancy, an added level of safety for you and even makes your dives more fun!  

What is a buddy team?

Buddy Team

Now that we know what a dive buddy is, you might be wondering “What is a buddy team”?

A buddy team is two to three divers that team up to dive together. A buddy team should never be any larger than three divers.

The reason why a buddy team should never be larger than three is that once your team becomes larger than three divers it becomes easier to lose track of each other and to lose a member of the team.

If you are diving in two as a buddy pair, then each diver is responsible for keeping an eye on the other diver throughout the dive. If one of the divers were to have an emergency, it would be easy for the buddy to spot it because they only have one person to look after throughout the dive.

Unfortunately, sometimes there is an uneven number of divers going on a dive and having just buddy pairs is impossible. This is when diving in a team of three comes in.

When diving in a team of three, each diver is responsible for keeping an eye on the other two divers in the team. As you can see, the more people are in a team the harder it becomes to keep an eye on everyone and manage an emergency should one arise. This is why we limit buddy teams to just three divers max.

If four divers are going on a dive together then two teams of two divers each should be established. Everyone can dive together, but the buddy teams need to be established before the dive.

How to Find A Dive Buddy?

Where do I dind a dive buddy

There are many places to find a good dive buddy. Looking for a dive buddy depends on your specific needs. Maybe you’re going on a vacation and you want to slip in a few dives but the person you are going on vacation with doesn’t dive. That’s different than if you’re looking to do more diving in the long term and want someone to go on dives with regularly. Here are some places to look for a dive buddy.

Your local dive shop

 If you live close to a dive center this is often a great place to meet other divers. The staff at the dive shop will often know who is looking for a dive buddy for a specific trip or even call people on your behalf to try to set up a dive. Additionally, if both you and the person they pair you up with both did your training at the same shop there’s a good chance that because of the similar training your gear will be similar, your underwater hand signals will be the same and you’ll have the same pre-dive buddy check procedures already in place. This makes everything simpler and smoother.

Your local dive club

Many cities have local dive clubs that meet regularly to dive, give presentations, and even share in meals and drinks. This is another great place to meet and find dive buddies. You can find out about local dive clubs through your local dive shop, local dive operators, social media searches and using google to search for local dive clubs in your city. 

Online Forums & Facebook Groups

Another place to find dive buddies is the internet. Forums such scubaboard.com have dedicated sections for finding dive buddies. You can also try Facebook groups dedicated to SCUBA diving. There are entire web sites such as divebuddy.com which are dedicated to finding a dive buddy. If you are single and looking to date a SCUBA diver there are even sites such as singledivers.com for that.

Continuing education

Taking SCUBA courses is another way to find new dive buddies. The advantage here is that you will be finding someone who is local, is also interested in learning more about diving, and if the class is a specialty course the person will also be interested in the same type of diving that you are interested in.

Dive boat operator

It’s common for divers to show up for a dive without a dive buddy and to have the divemaster or captain pair up the single diver either with another single diver or with an established buddy pair. If you choose to go this route you should check first before simply showing up. Not all dive boat operators will pair you up with a buddy team if there isn’t another single diver, and some may insist you pay to have a divemaster guide you. Simply showing up to the dive boat and blindly being paired up with a dive buddy should be your last option since you have no idea what who you will end up with as your dive buddy.

Hiring a professional

Sometimes the best option is to have a personal guide. This may be especially true if you are vacationing and want someone who can show you all the cool spots to ensure you don’t miss anything. It may also be a good idea if you are traveling and don’t have a lot of experience. By diving with someone who is a professional you may get pointers on your diving technique and gain valuable experience as you build your confidence up. It also ensures you are getting a competent dive buddy should something go wrong. 

Long Term Dive Buddies (what to look for)

It’s one thing to find a buddy to pair up with for a dive trip you’ll be doing on a vacation, it’s another to find a long-term dive buddy to go diving with often and to share your passion for SCUBA diving with over many dives.

If you’re trying to find someone to dive with over the long run here are some things to consider when finding that person.

2 buddies on beach dive

Do they live close to you and have the time to go diving? 

If a lot of your diving will be local diving, you’ll want your long-term dive buddy to live close enough to you and the dive sites you’ll be diving together so that it’s not an obstacle. Similarly, you’ll want them to have the free time necessary to go diving. What good is a dive buddy that never has the time to go diving?

Do they have similar experience?

While you and your dive buddy can have different certification levels and even dive experience, it is something you want to consider. If you have a lot more diving experience and training, you’ll likely be taking on the role of the dive leader within the buddy team more often than not. You may also need to cater the diving you do to the experience level of your dive buddy. If your dive buddy isn’t comfortable with a certain type of dive because of their limited experience you need to keep that in mind. You never want to push them to do dives they may feel uncomfortable with.

On the flip side of the coin, if you’re the diver with less experience or a lower certification level, you need to communicate what you are comfortable with and not comfortable with. The plus side of being the less experienced diver is that you can learn a lot from a more experienced diver.

Do you have similar dive objectives?

What do you like to do on your dives? Do you like to take pictures, capture video, or maybe just relax on your dives? What kind of dives do you enjoy? Do you like shipwrecks or reefs? Do you prefer night diving or maybe drift dives? The point I’m trying to make is that you and your long-term buddy ideally should want to go on the same kind of dives and partake in similar activities during the dive. If your buddy is always taking their time in one spot to get that perfect macro shot of a nudibranch and you want to swim and see as much of a site as possible it can become a conflict and neither one of you will enjoy the dive.

Are they significantly larger or smaller than you?

Part of being a buddy is being able to render assistance if needed. If your buddy is much larger or smaller than you then it will affect your ability to be able to tow them if the need should ever arise. Also, different sized divers usually have different breathing rates. All things being equal, a petite 100-pound woman will have a much lower breathing rate than a large 250-pound man. Using different tanks can, of course, make it so that gas doesn’t cut the dive short for the smaller diver, but it is something to consider.

What kind of gear configuration does your buddy use?

An often-overlooked part of being a dive buddy is that the gear your dive buddy uses will affect your diving. If your buddy always uses a smaller tank than you, you might become frustrated by a buddy that is always calling the dive while you still have plenty of gas to continue diving.

Similarly, if you use a dive computer with a very conservative algorithm and your buddies dive computer is more liberal, that can also become an issue with the diving you want to do.

Sometimes there are major differences in gear. Maybe you dive a traditional single tank that is back mounted, and your buddy always dives sidemount. Perhaps your buddy uses a rebreather, that too can be a consideration that can affect the way each of you wants to dive.

Does your buddy dive Nitrox?

If you are doing deeper dives this is especially important. You and your buddy should have similar mixes on the dives you are doing. Otherwise, the dive profiles and no-decompression limits for the dives you’ll be doing might be different. If you normally dive with Nitrox so should your buddy.

Do you get along?

SCUBA diving is a social sport. You’ll be spending time with your diving buddy. You’ll need to plan your dives, possibly spend time on dive boats getting to and from the dive site. You might also drive together to the dives and maybe even spend time after the dive sharing a meal. That’s a lot of time with your dive buddy. You want to make sure this person is someone you generally get along with and that you enjoy spending your time with them.

Different Dive Buddies for different dives?

Sometimes you'll want to have different dive buddies for different activities. Maybe one dive buddies loves shipwrecks but doesn't really like going on reef dives. A different dive buddy loves going on reef dives but doesn't particularly like shipwrecks. You like doing both. There's nothing wrong with having different dive buddies for different dives.  

What are the responsibilities of a dive buddy?

Buddy checking Regulator


Now that you know what a dive buddy is, where to find a dive buddy and what to look for in a good long-term dive buddy let’s discuss what your responsibilities are as a good dive buddy.

Pre-Dive

Before going on your dive, you’ll need to discuss several important elements of the dive you’re about to do with your buddy as well as perform some safety gear checks. You don’t want any surprises or confusion underwater, so this is when we clear everything up and get prepared for the dive to come. What follows are the minumum items to discuss and review with your dive buddy before every dive.

Getting to know a new buddy

If this will be your first-time diving with a new buddy there are several things you want to learn about them. First and foremost, you need to learn what their certification level and diving experience is. An advanced diver that’s only done 12 dives all of which have been part of a course is not the same as someone who’s been on a couple of hundred dives. You want to get a general feel for what their diving experience is so you can figure out who should lead the dive and also what your buddy may or may not be comfortable with.

Besides, understanding their experience you also want to know what hand signals they use for things like turning the dive, communicating air pressure, and emergency hand signals. Sometimes divers use different hand signals so it’s important to know how you and your buddy will communicate underwater. This is also a good time to ask if your buddy has a slate in case there is something you need to communicate underwater that can’t be expressed through hand signals. If you use a slate, you’ll want to let your buddy know that as well.

Another important topic that needs to be discussed with a new dive buddy is how to handle possible emergencies. These are some of the things you need to know:

  • Does your buddy give away their octopus for buddy breathing or do they donate their primary?
  • Where is the octopus on their dive rig?
  • Do they know how much ballast they need? (Ask)
  • How would you release their ballast in case of an emergency?
  • Do they have integrated weights on their BCD or are they using a weight belt?
  • How would you get them out of their gear in case of an emergency?
  • Does your buddy carry a Delayed Surface Marker Buoy (DSMB) and know how to use it?
  • What procedure do they follow in case of a lost buddy?

You want to know these things ahead of time, just in case the need arises.

Planning the dive

Now that you’ve gotten to know your dive buddy it’s time to plan the dive you’re about to go on. First, you need to communicate to your buddy what your objective is for the dive. If you plan to just relax and take in the sights let them know. If your dive plan is to take pictures or video, you need to let your buddy know this as well. Both you and your buddy must be on the same page regarding what you will be doing throughout the dive.

You and your buddy also need to decide on when you will turn the dive and how you will communicate that it’s time to turn the dive. Similarly, you should also discuss what your no-decompression limits are for the dive and how you plan to keep track of your limits. If you are using a dive computer, you might also want to discuss whether your computer is configured to be more liberal or conservative and how that may affect your bottom time.

This is also the time to decide on who will lead the dive. It’s best to have one person leading and the other following. If one diver has more experience with underwater navigation or simply has experience diving a particular dive site, they should be the leader. If you’re unsure as to who should be the leader because you both have similar experience than just pick a leader or take turns on different dives.

Finally, there might be special considerations your buddy needs to know before the dive. Maybe you take a long time to equalize your ears, or you prefer to extend your safety stops. Perhaps you know that you tend to breathe at a faster rate than most divers. If this is the case, you want your buddy to know before the dive so that there aren’t any surprises or any confusion during the dive.

The Buddy Check

Before going on the dive you’ll need to assemble your SCUBA gear and put it on. As you probably learned in your dive class this process should be done together with your buddy so that you can cross check eachother and make sure everything works properly.

Depending on the type of diving you are doing, you and your buddy may need to help each other to put on the SCUBA gear. If one buddy needs to lift the dive gear for the other buddy, the larger/stronger diver should put their gear on first. This is because they will need to hold the weight of their gear as well as the weight of their buddy’s gear for the longest amount of time while suiting up.

Diver setting up gear

Once your dive gear is assembled and you’ve donned your gear, before entering the water you need to check your gear, as well as cross-check your buddies gear to make sure everything is in working order. This is also often referred to as a pre-dive buddy check.

At a minimum you should check the following:

  • Tank
    •  is the valve fully open?
  • Regulator
    • Does the first and second stage breathe properly?
    • Is the SPG working and showing that the tank is full?
    • Do you hear any hissing sounds that may indicate any sort of leaks?
  • BCD
    • Is the tank strap tight and holding the tank in securely?
    • Does the low-pressure inflator inflate and deflate properly?
    • If the BCD has integrated weights, are they in place and secure?
    • Does the BCD hold air when fully inflated? (make sure there are no leaks)
    • Are all buckles and straps secure?
  • Weight belt
    • If one is being used is it on securely and also is the buckle easily accessible in case it needs to be ditched?

Different instructors and dive agencies have their methodologies and even acronyms to facilitate doing a buddy check, so the above list is by no means comprehensive. There are many different ways of doing a buddy check in the diving industry, so follow whatever system your instructor taught you in your class!

Diving the Buddy System

2 SCUBA buddies on a shipwreck scaled

Now comes what you’ve been planning and anticipating: The dive! The good news is that most of the hard work is done. By communicating with your buddy, having a dive plan, and doing the buddy checks you’ve gotten most of the work out of the way. There are still a few points however to keep in mind when diving with a buddy.

Maintaining the correct distance

The entire point of having a buddy is to have someone there to assist you should you need it. Your buddy acts as a safety diver for you, and you do the same for them. For this system to work you need to be within eyesight of each other. This will of course vary depending on the visibility, current, the topography of the dive site itself and whether you are diving at night or during the day. The main thing to keep in mind here is that should something suddenly occur such as an out of air emergency you should be no more than a few seconds swim from your buddy and you should notice it immediately.

In addition to staying within an appropriate distance from each other, you and your buddy should also maintain the same relative position throughout the dive. If you are diving to the left of your buddy, you should remain there for the entire dive. This way you each know in what general direction to look to find your buddy.

Dive the Plan

There’s a saying in diving. You plan the dive and then you dive the plan. Now it’s time to execute the dive plan. Because you discussed any objectives you have for the dive you can now execute those objectives. Maybe your buddy is taking photos so you can help find cool critters to photograph. Or perhaps your buddy would like to spear some lionfish so you’re on the lookout for them. The point here is that you and your buddy are a team working together underwater.

Also, because the dive has already been planned you know what your no-decompression time limits are, what your maximum depth should be throughout the dive, and when the dive will be turned. There are no surprises here.

The person who will lead the dive has been chosen before the dive so that buddy is responsible for navigating the wreck or reef.

Because hand signals and communication were established pre-dive you can now communicate with your buddy about things like your tank pressure, when to turn the dive, and any other relevant information.

When it comes time to ascend you know if your buddy will be doing a deep stop, how long they like to take on their safety stop and what their ascent rate is like (some divers like to come up slower than others).

Finally, because much of the dive has been planned out you’ve eliminated many of the things that can cause stress. You can now relax and enjoy the dive. This is why you’re here after all!

Post dive

One of the most neglected parts of the buddy system is the benefits it affords you after the dive. Just because you’ve successfully completed a dive doesn’t mean you and your buddy should go your separate ways. There are still several activities that great divers will do with their buddy’s post-dive.

Your gear still needs to be broken down, rinsed, and put away. Sharing in these duties with your buddy will make things easier, help to ensure you don’t forget anything and make carrying all the heavy gear less of a burden.

You should be keeping a logbook of your dives. Here, once again your buddy Is useful. By completing your logbooks together, you can compare notes. Did you think you had 70 feet of visibility or 90? What was the name of the site you did your second dive on? If you’re working on your diving performance, this is a good time to compare your Respiratory per minute volume or RMV. Who had a better breathing rate and why? How was your kicking technique, buoyancy, and trim during the dive?

You and your buddy can help coach each other so that you become better divers. What can you work on to make your next dive better? These are all things to discuss and document in your logbook so that you become a better diver each time you go diving.

Also, if you and your buddy were shooting photos or videos throughout the dive this is a good time to make copies of the photos or videos for each other.

How to Be a Good Dive Buddy

Dive buddy team on surface of the water

By following everything discussed in this article you will be a good dive buddy. These are some additional things you can do that will make diving with you even more enjoyable:

  • Move at the pace of the slowest diver. There’s nothing worse than having a buddy that is swimming at a pace that you feel you have to keep up with. Not only will both of you go through your gas supply faster than needed, but you’ll also likely miss out on some of the cool things to see on your dive. There’s no shame in being a slowpoke. SCUBA diving is supposed to be a relaxing sport!
  • Listen closely and take notes during the dive briefing. Two ears are better than one. It’s easy to miss some detail about the dive site or the dive in general. By listening closely and taking notes you ensure that if your buddy missed something you can fill them in.
  • Communicate early and often. Your air pressure, time left on your computer, and when you want to turn are all just examples of information that your buddy probably wants to know. There’s never any harm in communicating this information early and often. Also, if you are having issues such as equalization issues, feeling cold, tired, or even narced you don’t want these feelings to build up until they are unbearable before telling your buddy. The sooner you let them know the better. They may be feeling the same and decide to call the dive. Communication is key to being a good buddy.
  • Be on the lookout for equipment issues, even if they are small. Sometimes there’s a small leak coming from the SPG that wasn’t audible on the surface. Or perhaps your buddies fin strap looks like it’s about to break. Maybe a flashlight that’s in your buddies pocket accidentally turned on. These are all things your buddy should know about. The SPG hose probably needs replacing before the next dive, the flashlights batteries are being drained and might need recharging. Your buddy might need a new fin strap. These are all just examples of small equipment issues that sometimes aren’t noticed on the surface but become evident during the dive.

What about bad buddies? 

Unfortunately, sometimes you’ll come across someone who just isn’t a good buddy. Below are some signs that they may not be someone you want to have as a long-term dive buddy.

  • They constantly want to push things to the very limit. We all know the diver that gets back to the boat with barely any gas left in their tank. Or the diver that wants to say down until their computer shows that there is less than a minute left before they go into deco. If your buddy is constantly pushing the limits, they are not only putting themselves in harm's way, they may also be putting you into a dangerous situation.
  • They have very poor buoyancy, trim, and kicking techniques. They may even be one of those divers that inadvertently damages the reef because they are touching it due to their poor diving skills. If they are new and open to suggestions on how to become a better diver, it might be ok to continue diving with them. If, however, they are experienced and unwilling to work on becoming better, you might want to look elsewhere for a dive buddy. These divers also tend to suck through their gas supply very quickly!
  • They insist on being the dive leader no matter what! During the dive, you realize that they are not following the agreed dive plan and what’s worse, they have no idea of how to navigate the reef you are on. You might give them the benefit of the doubt, but eventually, you realize when the time comes to turn the dive that they have no idea what direction to swim in to return to the boat. Boat checks are now in order and if the visibility is poor or the currents aren’t cooperating you might have to do more than one before getting back to the boat. If this happens once or twice it might just be poor judgment. If it’s a pattern that’s a person you probably shouldn’t dive with.
  • You just don’t get along. There are a million reasons why some people might just not get along. Diving is supposed to be fun. If the person you’re diving with isn’t pleasant to be around you might be better off finding another dive buddy.

What About Solo Diving?

With all that is required for buddy diving, you might be wondering if it might just be easier to do solo diving. Some agencies in the diving industry have even created a certification for solo diving. While solo diving has pros and cons which are way beyond the scope of this article it’s important to know that many dive operations will not allow you to solo dive. Because solo-diving requires you to have completely redundant systems in case of an emergency and a much higher level of training, some even consider it to be a form of technical diving.

One other drawback to solo diving is that you simply do not have someone to share the diving experience with. Diving is more fun when it’s shared with someone.

Conclusion

At the end of the day being someone’s dive buddy is a type of relationship, even if it’s just for a dive. It’s important that you pick someone you are compatible with, that you know is competent and that you will enjoy your diving with. Having the right dive buddy makes diving safer and more fun!

You also want to be the kind of diver that others want to pair up with. So knowing and using the buddy system is critical to attracting the right kind of buddies.

What do you look for in a dive buddy? Is there something we missed? Let us know in the comments below.

Scuba Hand Signals

By Carlos Sagaro

If you are anything like me, you’ve had at least one time in your life when you were diving and you felt the frustration of not being able to tell your buddy something important. Maybe it was a once in a lifetime encounter with a shark, or perhaps it was something more important like letting your buddy know that her regulator's first stage was leaking air.

Whatever the reason, not knowing the correct hand signal can be frustrating and possibly even dangerous. 

As divers, we are in a unique position in that we often need to communicate without our voice. Diving with a buddy requires us to be able to communicate underwater using diving hand signals.  

We all learned a series of hand signals when we took our dive courses.  The reality is that we tend to forget them as time goes on.  Just like anything else, the less we use them the more we tend to forget what they are.  

In this article, we will be going over 70 scuba SCUBA hand signals that we feel every diver should add to their skill set to be able to be the best diver and buddy that they can be. The good news is many of these are commmon sense and easy to remember. Keep reading so you can see for yourself. 

A couple of things to remember before we get started.  First, make sure you complete your hand signals deliberately and slowly.  When you are underwater being deliberate will make it easier for your buddy to figure out what you are trying to tell them.  Second, before a hand signal is done, your buddy needs to be looking at you.  I know this sounds like common sense, but it can be easy to forget that you cannot just turn around and yell “hey” to get your buddy’s attention underwater.

Getting your buddy’s attention

There are several ways to get your buddy’s attention underwater.  One of the most common is to use a tank banger, a tool that is attached to your tank that allows you to bang against your tank to create noise.

If you do not have a  tank banger, you can the clips on your flashlight or any other metal object  to bang against your tank to make noise.

Another way to get your buddy’s attention is to yell through your regulator or clap your hands underwater.  In both cases, the buddy needs to be close enough to you to hear it.

The SCUBA hand signals in this article have been broken down into three different sections.  Essential SCUBA Hand Signals, Emergency SCUBA Hand signals and SCUBA hand signals for common marine life. 

(Note: If you'd like to learn more about how to choose a dive buddy, ready out article here: How to find the perfect dive buddy and use the buddy system so that your next dive will be amazing

Essential SCUBA Hand Signals

Okay

SCUBA Hand Signal Okay

This is the universal signal for letting your buddy know you are okay or to answer your buddy should he or she as you a question.

Go up or Ascend

SCUBA Hand Signal Go Up or Ascend

This lets your buddy know that you want to ascend. 

Go Down or Descend

SCUBA Hand Signal Go Down or Descend

This lets your buddy know you want to descend.

End Dive

SCUBA Hand Signal End the Dive

This is similar to the ascend signal but tells the diver it is time to ascend and end the dive. There are times when you may need to call a dive before you originally planned. In 9 reasons to call a dive we explore the various reasons. 

Come here or come closer

SCUBA Hand Signal Come Closesror Come here

Lets your buddy know that you want him r her to come towards you.  This can be done with one or two hands.

Slow Down

SCUBA Hand Signal Slow Down

This alerts your buddy that you want to slow down.  It can be done with one or two hands

Stop

SCUBA Hand Signal Stop

Tells your buddy to stop where they are.

Look

SCUBA Hand Signal Look in a Direction

Tells your buddy to look at something or in a particular direction. 

Go in a Specific Direction

SCUBA Hand Signal Look in a Direction

You will point in the direction you want your buddy to look at.  Please note that is done with an open hand.  Doing this with a close hand has a different meaning which we will go over later.

Buddy Up

SCUBA Hand Signal Buddy Up

This SCUBA hand signal alerts your buddy to dive with you.

Level Off

SCUBA Hand Signal Level Off

Tells your buddy to adjust his or her buoyancy at a specific depth.

3 Minute Safety Stop

SCUBA Hand Signal 3 Min Safety Stop
3 min safety 2

This signal alerts your buddy to complete a safety stop for three minutes at 15-20 feet.  Please note that this can be done in two difference ways.  The second method allows you to adjust the time depending on your specific practice.

Decompression

SCUBA Hand Signal Decompression

This diving hand signal alerts your buddy that you must complete a required decompression stop.  

Even though you should NEVER enter into decompression without the proper training and equipment this signal is useful to let your buddy know how much time you have on your computer before you reach your no decompression limit. 

Cold

SCUBA Hand Signal Cold

Lets your buddy know you are cold.

Question

SCUBA Hand Signal Question

Alerts that you have a question for your buddy

Leak/bubbles

SCUBA Hand Signal Leak Bubbles

This is used to let your buddy know that there is a leak coming from somewhere on their gear.  You can point to the area on your rig to let them know where their leak is.

Write it Down

SCUBA Hand Signal Write it Down

Alerts your buddy that you want him or her to write something down on their slate.

How to Communicate Numbers 1 – 5

SCUBA Hand Signal Numbers 1 - 5

How to Communicate Numbers 6 – 9

SCUBA Hand Signal Numbers 6 - 9

How to Communicate 100s

SCUBA Hand Signal Numbers 100s

The first number indicates how many hundreds.  In this case we are communicating 100.

How to Communicate 1000s

SCUBA Hand Signal Numbers 1000s

The first number indicates how many Thousands.  In this case we are communicating 1000.

Inflate the BCD (a little bit)

SCUBA Hand Signal Inflate the BCD

This tells your buddy he or she needs to inflate or deflate their BCD a little bit at a time.

Just a reminder, you always want to make sure you have done a proper buoyancy check before the dive. By doing so you minimize the amount of air you'll need to add to your BCD. 

Deflate the BCD (a little bit)

SCUBA Hand Signal Deflate the BCD
SCUBA Hand Signal Deflate the BCD

This tells your buddy he or she needs to inflate or deflate their BCD a little bit at a time.  There is more than method to do this, as seen above.


Inhale and Exhale Slowly

SCUBA Hand Signal Inhale and Exhale Slowly

This SCUBA diving hand signal tells your buddy to remember to breath in and out slowly.  Can be used to calm your buddy down.

Where is the boat

SCUBA Hand Signal Where is the Boat

Asks where the boat is relative to your location. If you are unsure, it may be time to get your compass out and do a boat check

You Lead I follow

SCUBA Hand Signal You Lead

Tells your buddy he or she will be leading the dive.  If you point at yourself first, you are telling your buddy that YOU will lead the dive.

Hold Hands

SCUBA Hand Signal Hold Hands

This tells your buddy you want to hold hands.  It can be used under several different situations including low vis, issues with gear, general anxiety, etc..

Essential SCUBA Hand Signals on the Surface

Okay

SCUBA Hand Signal Okay on Surface
SCUBA Hand Signal Okay on Surface

This is the universal signal for letting your buddy know you are okay or to answer your buddy should he or she as you a question.  This can we done with one or two hands.

Pick Me Up

SCUBA Hand Signal Pick Me Up

 Let the boat know you want them to pick you up

Emergency SCUBA Diving Hand Signals

Out of air

SCUBA Hand Signal Out of Air

Alerts your buddy that you are out of air and need to begin air sharing procedures

Something is wrong

SCUBA Hand Signal Something is Wrong

This alerts your buddy that there is something wrong.  It is usually followed by a signal alerting what the problem is.

Stomach Problem

SCUBA Hand Signal Stomach Problem

Start with the something is wrong SCUBA signal and point to your stomach.

Equalization Issue

SCUBA Hand Signal Ear Trouble

Start with the something is wrong SCUBA signal and point to your ear. If you'd like to learn more about how to avoid ear equalization issues make sure to read our complete guide on how to equalize your ears. 

Nitrogen Narcosis

SCUBA Hand Signal Nitrogen Narcosis

Alert to your buddy that you are feeling narked so he or she can assist you accordingly.

Air Sharing

SCUBA Hand Signal Air sharing
SCUBA Hand Signal Buddy Breathing

Let your buddy know that you are in need of air sharing.  There are two ways to do this as seen above.

Lost Buddy

SCUBA Hand Signal Lost Buddy

Let someone know that you cannot find your buddy.

Danger

SCUBA Hand Signal Danger

Let your buddy know that there is danger.  Please note that in this case you will be keeping your fist closed.

Emergency SCUBA Diving Hand Signals on the Surface

Lost Buddy

SCUBA Hand Signal Lost Buddy

Start by telling them you are okay and let them know you do not know where your buddy is.

Need Help/Rescue

SCUBA Hand Signal Need Help rescue


Use to let someone on the surface know that you are in need of rescue as soon as possible.  This can be done with one or two hands.

SCUBA Diving Hand Signals for Common Marine Life

Shark

SCUBA Hand Signal Shark

There are several distinct shark species around the world.  This diving hand signal is the universal signal for them all.

Hammerhead Shark

SCUBA Hand Signal Hammerhead Shark

This SCUBA hand signal is used to let people know when a Hammerhead shark is nearby.  Due to their uniqueness, they are known to have their own hand signal

Triggerfish

SCUBA Hand Signal Triggerfish

There are several different species of triggerfish.  They are found in costal waters all around the world.

Goliath Grouper

SCUBA Hand Signal Grouper

Formerly known as the Jewfish, Goliath Groupers are known to roam the Caribbean coasts and off the coast of Brazil.

Turtle

SCUBA Hand Signal Turtle

There are several species of sea turtles and they are seen all around the world.  This is a SCUBA hand signal you will use often.

Stingray

SCUBA Hand Signal Stingray

Stingrays are known to roam coastal waters and are seen in tropical and subtropical waters all over the world.  They are known to sit under the sand and wait for prey.

Puffer fish

SCUBA Hand Signal Puffer Fish

Also known as Blowfish, these fish are known to be seen in tropical waters.  The majority of them are poisonous.

Octopus

SCUBA Hand Signal Octopus

The octopus is an eight-limbed mollusk.  They  are found in waters all over the world.  They can change their color to mimic their surroundings and spray ink into the water when spooked.  This SCUBA hand signal is used for all of the species.

Lobster

SCUBA Hand Signal Lobster

Lobsters are found of the coasts of several countries in warm and cold water.

Lionfish

SCUBA Hand Signal Lionfish

Lionfish are native to Indo-pacific waters but have invaded waters all over the East coast of the US and the coasts of South and Central America.

Jellyfish

SCUBA Hand Signal Jellyfish

Eel

SCUBA Hand Signal Eel

There are many species of eels found in waters all over the world.  They tend to live in crevices inside of reefs but have been known to be spotted free swimming as well.

Fire Coral

SCUBA Hand Signal Fire Coral

Fire corals are found on reefs in the Indian, Pacific, and Atlantic Oceans and the Caribbean Sea.  When touched, they sting the skin and cause irritation.

Dolphin

SCUBA Hand Signal Dolphin

Dolphins are mammals that are found all over the world.  they can be seen in fresh and salt water.

Barracuda

SCUBA Hand Signal Barracuda

Barracuda are found in tropical and subtropical oceans worldwide.

Crab

SCUBA Hand Signal Crab

Crabs are indigenous to waters all over the world.  They can be seen both underwater and on beaches  They reside in holes and hide in shells as well as trash.  There are many species of crab.

Boxfish

SCUBA Hand Signal Crab

Boxfish are native to the Atlantic, Pacific, and Indian oceans in tropical and subtropical zones.

Angelfish

SCUBA Hand Signal Angelfish

Manta Ray

SCUBA Hand Signal Manta Ray

Manta Rays are found in most waters around the world.  They are filter feeders so they tend to move around constantly

Clown Fish

SCUBA Hand Signal Clown Fish

Clown Fish are found in the warmer waters of the Indian Ocean, including the Red Sea and Pacific Oceans, including the Great Barrier Reef, Southeast Asia, Japan, and the Indo-Malaysian region.


9 Reasons To Call a Dive

By Carlos Sagaro

Calling A Dive: 9 Reasons to Stay Safe and Dive Another Day

Pop quiz! You’re descending down the line with a new dive buddy.

As soon as you reach the bottom you begin second guessing whether or not you even want to do this dive.

Maybe it’s the fact that something about this guy, his gear, or his attitude about the dive just doesn’t seem right. Maybe it’s the fact that current is bit stronger than you expected or that the visibility isn’t all that great.

Is it ok to end the dive? Should you call the dive?

This is a great question and the answer can vary from person to person. Knowing when you absolutely must end a dive versus when it is okay to just deal with a situation underwater is something you must consider BEFORE it happens.

If you’ve never thoroughly thought this through, make sure to keep reading.

First things first, in case you haven’t heard the term before, “Calling a dive” is simply diver jargon for ending a dive. Typically, the hand signal used between divers to let each other know it’s time to end the dive is the “thumbs up” hand signal.

scuba mask fogging up, SCUBA mask anti fog, defog scuba mask

No doubt that your introductory SCUBA diver course you were taught that your dive is over when you are getting close to your pre-determined reserve gas pressure, your no-decompression time limit, or the pre-determined time that the captain or dive master gives before entering the water. There are many other reasons why you may and in many cases absolutely should end the dive.

Reasons # 1-3: You’re Too Cold, Working Too Hard, or are Otherwise Uncomfortable

When learning about decompression sickness, you were taught to adjust the dive tables by adding a letter group when you are too cold or working too hard. By adding a letter group, you reduce your total bottom time underwater.

If you are diving with a computer you should be extra conservative with your bottom times when you are working harder than usual or cold.

In both the above scenarios, by shortening the bottom time you are reducing your chances of getting decompression sickness.

So, what exactly is overexertion?

scuba mask fogging up, SCUBA mask anti fog, defog scuba mask

The most common cause of overexertion in diving is probably swimming into a current that is too strong.

If you are having to kick nonstop just to hold your ground underwater, then you’re most likely going to end up breathing harder than usual and overexerting yourself.

Other causes of overexertion can be swimming too fast, swimming with too much ballast, inefficient trim, bad buoyancy control, or an inefficient kicking technique.

Overexertion happens because you are working too hard. What a lot of people do not realize is that it can also happen because you are cold.

When you are cold your body will work to keep your body temperature up. Eventually we all know that if you stay cold long enough you’ll begin to shiver. All of this bad because it causes ingassing of nitrogen. 

However, there are times when we are working so hard or are so cold that our dives are no longer enjoyable.

scuba mask fogging up, SCUBA mask anti fog, defog scuba mask

Think about it, for the majority of us, SCUBA diving is a hobby we do to de-stress or to enjoy some R&R. I don’t know about you, but for me there is nothing relaxing or stress relieving about feeling overly cold or overly exerting myself. I mean, I love a good workout as much as the next guy, but not while I am underwater breathing compressed gas.

Bottom line, if you are in a situation where you are no longer comfortable underwater due to heavy surge, current or because the water is just too cold, it is a good idea to stop your dive and begin a nice, slow ascent performing a safety stop before exiting the water.

Reason #4: Your Regulator is Leaking or Performing Strangely

Your regulator is essential to SCUBA diving. Many people do not think about it however, it is life support equipment!

When all is said and done, we cannot spend very much time underwater without it. We count on it to keep us alive and to breathe easily while we enjoy the underwater world.

The problem is that often we do not “listen” to what our gear is telling us.

Bubbles streaming from the SPG or second stage, a leaky alternate air source that you need to keep covering up constantly during the dive, or even having more gas delivered to you from your second stage as you are exhaling are all signs of a regulator that needs servicing.

scuba mask fogging up, SCUBA mask anti fog, defog scuba mask

The problem is that all of these warning signs can suddenly get worse. A significant change in your regulator’s performance or a stream of bubbles indicating a leak is a sure sign that you should cancel your dive immediately and slowly ascend to the surface while you still can. There is no reason to risk having an equipment malfunction while underwater.

Reason # 5: Your Dive Computer Fails or is Behaving Strangely

As stated earlier, as divers we rely on equipment to keep us alive and safe under water. Dive computers have become a staple for most avid divers. However, because they are electronic devices they certainly can fail underwater.

A funky reading (telling you you are at 100 feet (33 meters) when you know you are way shallower, a fading screen that looks like the computer is about to die, or of course if the computer just stops working for whatever reason.

These are all reasons to call the dive!

Because we depend on dive computers to keep us safely within the no-decompression limits it is extremely important for us to recognize that if this vital piece of equipment fails it’s time to call the dive.

Dive computer small

NOTE: You should never use 1 dive computer for 2 buddies. A dive computer tracks the nitrogen in-gassed by each dive based on their unique dive profile. Because every diver will usually have a different dive profile (there is no way to be at exactly the same depth as your buddy on most dives), you should never share a dive computer. This is why if this instrument fails, it’ time to call the dive.

Reason # 6: Your timing Device Fails

If you are not diving a computer and your watch fails you must stop your dive and perform a controlled ascent with a safety stop. Not doing so can be very dangerous since you have no way of determining the time that you have spent underwater.

Reason # 7: Your Dive Buddy Makes You Feel Uncomfortable

This one certainly can be one of the most difficult situations to deal with, especially if your dive buddy is someone you know well or have been diving with for years.

At someone point in our lives, we have all felt peer pressure. Something is happening and you do not necessarily feel comfortable with it but you go along because you want to “fit in.”

It can be challenging to say “no thanks” but when you’re SCUBA diving, it is imperative that you always do things that you’re comfortable with. Diving with anxiety can be the precursor to a potentially serious diving accident.

Divers on line 1

When you are diving with a buddy, it is important that you communicate what your limits are before you get in the water so that expectations can be set. If those limits are pushed or something happens where they are broken, you should be ready to call the dive confident in the fact that you have done the right thing for yourself and your safety as a diver.

It is always better to have an uncomfortable conversation than to have to be taken to the hospital.

Reason # 8: You Don’t Feel Safe

If you are on a dive and you start to feel the “heebie jeebies,” it is a good idea to end your dive. The reasons for this is simple, feeling unsafe can certainly lead to anxiety about the dive you are on.

Being anxious is not the state you should be in if a situation arises that you need to deal with underwater. Dealing with a diving emergency, or even a diving nuisance when you are calm, cool and collected is not the same as dealing with it when you are already mentally stressed.

Being anxious can lead to all kinds of mistakes that otherwise would never happen.

It is always better to dive another day than to end up wishing you had just followed your instincts “that one time.”

Reason #9: Any Other Reason at All

“Any diver can call a dive at any time for any reason!”

This is something we teach all of our students in their entry level SCUBA diver course. It is something that I have instilled in all my students and reiterate to them throughout their classes at all levels.

Because SCUBA diving is a recreational sport, there is no reason to be on a dive if you are not comfortable while doing so.

Also, because you may depend on your buddy in case of an emergency it’s important for them to be comfortable and able to perform when needed. This means they need to be in a state where they are calm, cool and collected.

Scared Diver Small

This is why any diver can call a dive at any time for any reason.

What other reasons do you think should be included in this list? Let us know in the comments below:

Warning: Why Your Weighting May Be All Wrong and How to Fix It

By Carlos Sagaro

If you’re like most divers, you probably have a set amount of weight that you carry with you as ballast when you dive

What you may not realize is that how you carry that weight is almost as important as the amount of weight itself.

Have you distributed that weight evenly across your rig so that your trim is balanced and you’re comfortable during your dive?

What would you do with the weight you carry with you in an emergency?

Is it important to you to be able to ditch your weight? If so, how much?

If you’re curious about the answers to any of these questions, then you’re going to want to read on.

In this article, we’re going to discuss a hot topic which is often overlooked yet critically important to your buoyancy control, trim, comfort and even your safety when you go diving.

One of the things that is counter intuitive when you learn to dive is the fact that you need to add weight to SCUBA dive.

Using an incorrect amount of weight when diving is one of the most common mistakes that many divers make. In many cases, people are diving with more weight than they need.

The cause may be doing an improper buoyancy check, sticking to weight that’s always been used but never tested, or simply adding more weight than what is really needed and compensating for it by adding air to the BCD.

Whatever the reason, in this article, we are going to dig into weighting and how you can use it to your advantage to improve your buoyancy, comfort level, breathing rate, and over all diving experience.

Why is Weighting Important?

Knowing and understanding how to be properly weighted will do wonders for you diving experience.

If you are over weighted or under weighted, your experience underwater is going to suffer. Let’s dig into some examples so you can see how:

Still Diver

What happens when you are over-weighted? 

First, imagine you were diving just 6lbs overweight. There are several problems which you will encounter. let’s go through them one at time.

  • Extra weight to carry around needlessly: That extra weight is going to need to be carried on and off of the boat. You may also be carrying it in your gear bag which is already heavy enough as is. What’s the point of carrying around dead weight that’s not needed?
  • Your propulsion may suffer: Every time you kick you’re moving more weight around than what is needed. It’s not just that weight itself. Because you need to compensate for the extra weight to stay neutrally buoyant you need to add extra air into your BCD. That extra air creates additional drag. This means more weight AND more drag in the water.
  • Your rig is likely off balance: It’s not just the amount of weight that you carry into the water, it’s where you position it that makes a difference in your diving. If like most divers you’re simply adding more weight to a weight belt or a BCD with ditch-able weights, there’s a good chance that, when you stop moving in the water column, your body is not in a balanced horizontal position like it should be.
  • It’s harder to get into and out of the water: That extra weight makes it harder to climb boat ladders. Even if you’re taking your rig or weight belt off and handing it up to climb on to a boat it’s still extra weight that doesn’t need to be there.
  • It can be extremely unsafe in the event of an emergency: If your BCD bladder or wing were to fail underwater this is now extra weight that you will need to swim up. If you ditch it, it may make it impossible to hold a safety stop or even lead to you having a fast or an uncontrolled ascent to the surface.
Diver Aluminum Tank

What if you were to be diving under-weighted? The circumstances are different, but just as serious.

What happens when you are under-weighted? 

  • Not being able to compensate for consumed gas: One of the reasons you may need to carry additional weight is to compensate for the shift in buoyancy which happens as you consume the gas in your tank. The video below explains this shift in gas that happens when you dive.
    • This is especially prevalent when you use aluminum tanks. As you consume the gas in your tank, it becomes lighter and lighter. Eventually the weight of the gas that was keeping your buoyancy negative is no longer there. It’s at this point that you find yourself having to fight to stay down.
  • Needing to change your body position to stay underwater: When you do not have enough ballast, you cannot hover effortlessly underwater. Because of this, you need to either kick or hold on to something to keep from floating up. Needless to say, if you are kicking to stay down you’re consuming the gas faster and the cycle becomes worse and worse as you have less gas and less gas in the tank.



Types of Dive Weights

Now that you understand why it’s incredibly important to be properly weighted, let’s start at the beginning. There are several types of weights used by divers and each one of them has its pros and cons. In this section we are going to discuss a few of those systems and their characteristics.

Solid Lead Weights

Every diver has come across solid lead weights at one point or another in their diving. These are a tried and true type of weighting system.

Hard Weights Small

To be thorough, because the name itself implies what they are, solid lead weights are a piece of lead molded to fit a weight belt. They come in a variety of sizes ranging from .5lb to 10lbs (.23 kg to 4.5 kg). In some cases, they are incased in rubber to make them more comfortable around the body and to minimize lead exposure.

The biggest plus about these weights is that they are the most compact and therefore produce the least amount of drag. They are one of the least bulky of the options. They also tend to last forever. They can be used both on a belt or inside BCD pockets. (more on this later).

The biggest con is that they can be uncomfortable if they’re in a position on your weight belt where they are hitting your hip bone. Also, you must be careful to not drop them as doing so can be very painful and can even cause injury if they land on your foot.

Beaded Lead Weights

SCUBA weights

These are also extremely common. They range in sizes starting at .5lb to 10lbs (.23 kg to 4.5 kg). They consist of lead beads that are incased in mesh to allow them to dry and so that water will not accumulate inside of them.

There are several benefits to these types of weights. They are softer which makes them much more comfortable to store inside of BCD pockets and pocketed weight belts. Being malleable, they can counter to a diver’s body which makes them more comfortable when work on a weight belt. Lastly, and this has saved many a diver, if dropped they cause little to no damage.

As for the cons, beaded lead weights tend to be a bit more expensive. They also are bulkier, especially when used on a weight belt. Finally, the life span is probably not as long as lead weights since the material used to hold the pellets inside can rip.

Using Your SCUBA Tank as Ballast

It is common knowledge that tanks come both in aluminum and steel. While many divers do not think of them in this manner, steel tanks can be used as a weight.

Steel tanks as ballast

Unlike aluminum tanks, Steel tanks tend to remain negative even when they are empty. Additionally, Steel tanks are generally heavier than aluminum tanks and therefore can be used as a form of ballast. Steel tanks also tend to hold more gas than a similar size aluminum tank.

Finally, because the weight of a steel tank is distributed evenly across your back, steel tanks are often a good choice because they make it easier for you to achieve good trim and body positioning while on a dive.

The cons to diving steel tanks are that they tend to be more expensive, require more maintenance, and are usually heavier out of the water.

Aluminum Tank Considerations When It Comes To Weighting

Unlike most steel tanks, aluminum tanks tend to start negative and then end up slightly positive towards the end of your dive.

Steel Tanks Small 1

Just like steel tanks, when you are diving with aluminum you must consider where the tanks buoyancy characteristics end up at the end of your dive.

If you are neutral with a full aluminum tank at the start of you dive, you will be positive at the end of you dive which could cause all sort of problems. This means that you need to carry additional ballast to compensate for the positive buoyancy caused by a tank that is floating at the end of the dive.

Aluminum tanks are the most common type of tank because they are generally cheaper and also easier to maintain.

The bottom line is, whether you are diving with a steel or an aluminum tank, you must be aware of the tank’s buoyancy characteristics when it is empty or near empty. The last thing you want is to be slightly positive at the end of you dive.

Additional Tank Considerations

It is important to note that all tanks tend to become less negative as they start to empty during a dive. Every tank is different, and tank manufacturers publish charts which you can use to determine which tank is best for you.

Using these charts, you can get a good idea of what the buoyancy characteristics of different tanks are. However, you should be aware that these charts are only a starting point in helping you determine the amount of ballast that you’ll need.

Tank manufactures usually list the buoyancy characteristics of a tank without including the weight of the valve or the tank boot (if there is one). Additionally, the buoyancy characteristics are listed for a completely empty tank (something you should never do). Finally, you should also note if the buoyancy characteristics are for salt water or fresh water.

Armed with this knowledge and knowing the amount of gas that you will need for a dive, you can choose the most appropriate tank for your needs.

Regardless of whether you have a new tank or if you are using the same tank you’ve always used, you should always perform a buoyancy check with the tank being at its reserve pressure, either with your SCUBA gear on, or off the gear by itself in order to determine its buoyancy.

Common Types of Weighting Systems

Weight Belts

Types of Belts 3 Small

Weight belts are exactly what they sound like. A belt that you use to hold weights when you dive. There are two types of weight belts. The first is a basic nylon belt that you slide solid weights onto. The second is a pocketed that you can slip weights into.

The nylon belts can only hold solid weights. If you use this type of belt you’ll also want to use a belt slide or stopper to keep the solid weights in their place.

The pocketed belt can hold both solid weights and beaded weights. Whether you are diving with a nylon or pocketed belt, they both should have a quick release in the event of a diving emergency. (we will go into ditching weights later in this article.)

Integrated weight pockets on BCD

It is fairly common for BCDs to have integrated weight systems. They usually consist of a removable weight pocket on the front side of the BCD attached to the cumber bun. 

Weight pouch Small

These can be used in lieu of a weight belt. Essentially you insert the needed weight into the pockets and then insert the pocket into its slot in the BCD. You can use both solid and beaded weights with these pockets.

Weight Pockets on Tank Bands and on the Back of BCDs.

Rear Weight Pouch Small

Weight pockets are often added to BCDs, usually on the back side to allow divers to add weight in other areas besides their waste to help with distribution and trim. They can be an integral part of your weighting because, in addition to providing needed ballast, they also allow you to improve your trim. They can also be added to the cam bands on your BCD should your BCD not have the pockets built in.

Backplates

These are normally used in conjunction with a harness and wing. In recent years, there have been a few more conventional BCDs that have been modified to use back plates as well.

There are generally two types of back plates, Steel and aluminum. Which you should use depends on your weighting needs and the type of diving you are doing. Steel back plates are generally heavier than aluminum and thus provide more negative buoyancy. 

Steel Back Plate

How much negative buoyancy they provide depends on the manufacturer, so it is important to find out how negative a backplate is in the water before you purchase it to ensure you are getting the best one for yourself.

The biggest positive attributed to back plates when weighting is concerned is the fact that they tend to distribute weight evenly across your back which provides more stability in the water by helping to placing your body in a horizontal body position. This is a huge advantage because having better trim reduces drag. This reduction in drag causes you to work less when under water which causes you to burn less gas and enjoy longer, less tiring dives.

There are two aspects to back plates that can be considered negative depending on who you ask (more about this later). First, backplates are a permanent part of your BCD and cannot be ditched in an emergency scenario (see the section on “ditchable” weights if you want to learn more about this). Second, the vast majority of jacket- style BCDs will not allow you to use a backplate. This is something to consider if you are thinking about switching to a back plate.

A note on Ankle Weights

Ankle Weights Small

While not as common as the other forms of ballast, there are people who use ankle weights when they dive. This is especially common when using a dry suit.

I do not recommend that divers use ankle weights. They make it more difficult to kick properly which negatively affects your efficiency under water. Their negative effects far outweigh any positive effect they can have in your trim.

The idea is that they help with keeping your feet down. When diving dry, air can become trapped near the legs and cause your feet to become positively buoyant.

If you feel you need more weight at your feet to help with trim, my recommendation is to look for a heavier fin, use one of the many wraps that are available to place around your lower legs to prevent gas from traveling to your feet. Or simply work on placing less gas into your dry suit. Having excess gas near your feet is a common beginners mistake when learning to dive with a dry suit.

Can you figure out how much weight you need using a calculation?

“Ten percent of your body weight!”

There is a common misconception with some people that you can use a formula to figure out how much weight you need in order to dive. One such formula which is the old “ten percent of your body weight” myth.

The truth is that there really is formula you can use to accurately calculate how much weight you are going to need when you dive. The only real way to do this is to get in the water and do a buoyancy check. The video below explains how to do a buoyancy check for yourself. 

How To Do A Proper Buoyancy Check: Part 1

How To Do A Proper Buoyancy Check: Part 2

Once you know how much weight you need for yourself, now you can determine the amount of weight you need for your gear. 

Do your ballast requirements ever change?

As stated in the previous section, only a buoyancy check can determine exactly how much weight you are going to need on a given dive. The reason why is because that number varies depending on several factors that we will go over in this section.

Types of Belts 2 Small
  • Your Gear: The equipment you use will certainly impact the amount of weight you are going to need when you go diving. When diving with a 5mm wetsuit, you are going to need more weight than when you diver with a dive skin or no exposure protection, simply because the thicker suit is more positively buoyant. The same is true if you switch from diving an aluminum tank to a steel tank or vice versa. Also, if you carry additional gear into the water such as reels, lights cutting devices etc.… All this equipment adds up and will affect the amount of ballast you need in the water.
Dry Suit Small
  • Shell Dry Suits: A shell dry suit is a suit designed to keep a diver dry which does not in and of itself provide thermal protection. Shell dry suits require undergarments that give you the desired thermal protection based on your needs and the water temperature. Because these undergarments tend to be more positively buoyant the thicker they get, you will need to adjust your ballast needs accordingly.
  • Your body: Your buoyancy characteristics can change if your body composition changes. Let’s face it, sometimes we let ourselves go and we gain fat. Perhaps at other points in our lives we go on a diet and lose some of the unwanted fat. These changes in your body composition can affect your weighting needs. The more body fat you have, the more weight you need to achieve proper buoyancy.
Ascent Line
  • Your Diving medium: Are you diving in fresh or salt water. Are you diving in an area that is known to have more salinity than the regular ocean? These things will affect your ballast needs. You will need to use less weight when diving in fresh water than when you are diving in the ocean. Diving in an area that is known for heavier salinity, The Dead Sea or Salt Lake come to mind.

Variables Which Will Change During the Dive

It’s important for you to know that in addition to needing to change your ballast requirements according to your gear, your exposure protection, fluctuations in your body composition and changes between salt and fresh water, there are also factors which could change during the dive.

  • Lung volume affects your buoyancy. The larger lung volume you have the more buoyancy shift you will feel as you inhale and exhale while you are diving. You can control this by thinking about how you breathe. By taking shallower or deeper breaths, you can make pinpoint adjustments to your buoyancy without having to make ballast changes. This is an important note to make since breathing deeper or shallower can affect your buoyancy throughout the dive.
  • Neoprene compression: When diving a wetsuit or neoprene dry suit, it is important to understand that neoprene compresses at depth. This is not so noticeable with wetsuits that are 3mm or less, however if you are diving with a 5mm or 7mm wet suit this fact is important, especially if you are diving deep (over 66 feet or 20 meters) where the neoprene will compress significantly. 

    This causes a change in its buoyancy characteristics. The thicker your suit, the more this becomes a factor. When selecting your ballast requirements, you must consider the suits buoyancy before the neoprene is compressed as well as after it compresses. We will get into more details as to why this is important when we go into the topic of ditching weights later in this article.

What About “Ditchable” Weights? Don’t All Weights Need to be “Ditchable”?

Most of us were taught in our entry level SCUBA course that we need to be able to ditch all our weight quickly so that we can properly manage an emergency.

When you think about it, it sounds like it makes sense. If there is an emergency underwater and you need to bring yourself or another diver to the surface, ditching the weight may make it easier since there is less ballast to bring up. This is especially true if the diver is unconscious and wearing a lot of lead. It is also easier to establish buoyancy on the surface when there is less ballast.

Now, before we move on, let me ask you something. In the above scenario, why does ditching the weight make everything easier?

I’ll give you a moment to think about it…

Do you know why?

It’s because most of the time the diver is over-weighted!

If a diver is properly weighted, it means that they are carrying just enough ballast to remain neutral at the end of the dive with the reserve pressure in the tank.

Think about it this way, if your tank is 3lbs positive at the end of your dive, you are going to need to add 3lbs of ballast to your rig to offset that change.

Now, let’s look at this using the example of a diver using an aluminum 80 (12 liter cylinder).

Aluminum tank Diver small 1

The weight needed to offset the positive buoyancy an empty aluminum 80 (12 liter tank) is around 4 pounds (1.8 kg) in salt water. Of course, it is highly unlikely you will ever dive with a completely empty tank.

At its working pressure, an aluminum 80 is about 2lbs (.9 kg) negative.

This means that, if you are properly weighted, you should at most be 6lbs (2.7kg) negative at any point during the dive.

6 pounds (2.7 kg) is NOT a lot of weight. Every BCD or wing on the market that can easily offset that amount of weight. It’s also an amount of weight that any diver should be able to swim up easily even if you were to have your BCD fail on you and not able to hold air.

Why am I saying this?

Because for many divers taking the weight off of their weight belt and distributing that weight either through weight pockets on the tank bands, a stainless steel backplate, or even by using a steel tank instead of an aluminum tank makes a lot of sense.

Distributing your weight around in this manner makes you more streamlined and puts you in a horizontal body trim position when you dive.

The bottom line is that, as long as you are not over weighted, whether your weight is ditchable or not will not be a big deal.

NOTE: There is an exception to this and it’s when you are diving in cold water and using a thick (7mm or more) wet suit or diving a dry suit (more on that later).

Why Ditching Your Weights Can be Dangerous!

What if you really need a lot of ballast to dive?

Cold Water Diver Small

Maybe you dive in cold water. If you do, I know, you need quite a bit more ballast than if you are diving in warm water. Using a thick wetsuit or a drysuit is very different than diving a 3mm wetsuit on a tropical reef.

Perhaps you just need more ballast because your anatomy requires it.

Either way, when you do a proper buoyancy check, you’ll know that you are diving with the amount of weight you need to offset the positive buoyancy of yourself and your gear.

As a rule of thumb, if that amount exceeds 8lbs (3.6kg) the practice of placing all your ballast either on your weight belt or in the ditchable pockets of a BCD while at depth can be dangerous.

You may be wondering why. It’s because, if you were to ditch all that weight at depth, you could possibly be placing yourself into a situation where you could go into an uncontrolled ascent the moment you lose all the ballast that was keeping you down.

Uncontrolled ascents can have catastrophic effects on a diver.

Things like an arterial gas embolism, decompression sickness, or a reverse block are all real dangers. There is also the danger of being finding yourself in an uncontrolled ascent while hearing the sound of an oncoming boat.

If you still choose to store all your weight in a system that makes it ditchable, you need to think about the possibility that you could accidentally lose all your ballast.

I’ve seen this happen many times over the years. A belt becomes loose or the Velcro that holds a weight pocket in place becomes worn and doesn’t hold as tightly any more. This could cause a diver to unknowingly lose all their weight.

The bottom line is that if you need a lot of weight to be neutral at the end of your dive, suddenly losing that weight can be dangerous. You need to think about where you are placing the weight that you need and why you are doing so.

When You Absolutely Should Be Able to Ditch Your Weights!

There is one scenario where you absolutely need to be able to ditch SOME of your weight. It’s when you are diving deep (over 100 feet / 30 meter) and using a wet suit that is 5mm thick or more.

Why? Because the wet suit will compress at depth. Neoprene is a material that is made up of microscopic nitrogen bubbles. Those bubbles compress the deeper you go.

This means 2 things:

  • Your wet suit will not insulate as well at deep depths as it does at shallower depths.
  • More importantly, because all those tiny microscopic bubbles are compressed, the suit will also be less buoyant at depth.

Because of this, you’ll need to compensate for the positive buoyancy that your suit loses at depth by adding gas to your BCD. It also means that you are more negatively buoyant at depth than you are when you are shallow.

Therefore, it is important for you to be able to ditch some of your weight at depth.

Should you experience a catastrophic event that renders your BCD useless, you may not be able to swim your way up to the surface because of the additional negative buoyancy caused by the compression of your wetsuit.

In this scenario, ditching some of your weight could save your life.

The above scenario poses a difficult decision. You may need to ditch some weight to be able to get to the surface but doing so puts you in a position where, once your suit becomes more positively buoyant, you could find yourself in an uncontrolled ascent.

Yes, it is a catch 22. The way I see it is, I would rather be slightly positive than extremely positive due to the fact that I had to ditch all of my ballast. This is why I think it is important to make only some of your ballast ditchable rather than all of it. The amount that you ditch should not exceed amount of buoyancy lost by the suit.

When Things Go Wrong: Abrupt Changes in Buoyancy

I have a confession to make. When I first started diving I thought that the chances of having a failure of your BCD or anything else that would severely affect your buoyancy was unlikely. Especially if you maintained your gear and always went diving with relatively new gear.

Boy was I wrong!

First, I had a dive where my own BCD broke at the elbow where the low-pressure inflator connects to the bladder.

About a year later I was doing a dive with a student and her high-pressure hose burst while on the dive.

A couple of years after that, I had a different BCD’s dump valve completely come off when I pulled on it to release some gas.

Over the years I’ve heard multiple stories just like these that happened to other people.

I’m telling you this because, if you dive long enough, you will experience equipment failures. It’s a part of the sport. Fortunately, if you are properly trained these are usually just minor annoyances as they were for me and my student.

There are several scenarios where your buoyancy can change quite rapidly and without warning. As a diver, it’s important for you to know about and plan for the possibility of these scenarios.

Equipment failures that can cause abrupt Buoyancy changes

Catastrophic equipment failures are not common but they can happen and it is important to consider these unlikely scenarios and how to handle them.

Becoming Positively Buoyant Unintentionally

Burst disk failure: In the event that the burst disk on the tank valve fails you will be put into a potentially dangerous situation. Firstly, you will be losing the gas in your tank quickly. Your ability to breath will be completely compromised and they tank’s buoyancy characteristics will change very abruptly.

Burst Disk Small 1

Regulator Diver small

A free-flowing regulator:  Should a regulator fail and begin to heavily free flow, the rapid loss of gas can affect buoyancy. However, the effect will not be as abrupt as in the scenario above.

The high-pressure hose or SPG (submersible pressure gauge) can burst also causing a rapid loss of gas.

Console

Becoming Negatively Buoyant Unintentionally

Wing Failure: Catastrophic wing failures have been known to happen. When wings fail in this manner, they tend to fail at the elbow of the low-pressure inflator or at one of the dump valves.  This renders the wing useless as a tool for buoyancy control.

A tear in the BCD is a possibility, however tears do not always render wings completely useless and are a lot less common. A leak in the bladder can also affect buoyancy, however the leak’s size and position may allow the wing to be at least partially useful as you ascend to the surface.

In any of the scenarios above, immediately ending the dive and ascending becomes of paramount importance. As we discussed earlier, controlling that ascent is also important because rapid ascents can cause all sorts of potentially life-threatening diving injuries.

The Case for Redundant Buoyancy

Being able to swim up without the assistance of the positive buoyancy of your bladder is something that every diver should consider. As we mentioned before, this is especially important if you are diving with thick thermal protection in cold water.

It is because of this that we recommend that you only dive with the amount of weight needed to offset your gas. This will make you just slightly negative in the event that you are in a scenario where your bladder is no longer functioning.

That being said, there are several avenues you can choose should you want to carry redundant buoyancy.

  • Redundant wings: There are wings that have two bladders in them. They are designed to offset each other in the even that one should have a catastrophic failure. They will require two low-pressure inflator hoses attached to two independent low-pressure inflators
  • A Dry Suit: A dry suit can be used as redundant buoyancy in the event of a catastrophic wing failure. This is because by adding extra gas into your dry suit you can make yourself more positively buoyant.
  • Lift Bag: This is the least desirable option. However, should you find yourself in a scenario where your bladder is no longer functioning, a lift bag can be used to offset negative buoyancy. If this is your only option, you must be aware that the bag cannot just be shot up to the surface from all depths and it is important to try to control the amount of lift the bag is providing you in this situation. Controlling buoyancy with a lift bag is not easy therefore it is the least desirable option.

Ditching Weight at the Surface

Diver on Surface 1

Many of us were taught that, if there is an emergency situation on the surface, we should ditch our weight as well as the victim’s weight. This is to establish positive buoyancy.

Every choice in diving has tradeoffs. If you dive a steel tank, a stainless steel backplate, or even some pockets on a tank band, you’re carrying some weight that may not be able to be ditched.

The tradeoff for not being able to ditch the weight is being more streamlined and having better body position in the water. Both of these allow you to have longer more enjoyable dives. You also avoid the negative consequences of losing your ballast at depth and having an uncontrolled ascent.

As mentioned before, as long as you are weighted correctly, the negative buoyancy created choosing to distribute weight in this manner should be minimal and easily compensated for by the BCD.

The real problem is that there are a lot of divers that are over weighted.

Ditching weights on the surface becomes crucial when a diver is over weighted. It’s when divers are over weighted that you MUST BE ABLE TO DITCH THE WEIGHT. Not being able to do so makes it difficult to establish positive buoyancy.

So, the bottom line is, if you dive don’t be over-weighted. If you have buddies who dive, don’t let them be overweighed, and if you want to help other divers become aware of this topic, make sure you share this article.

As you can see, there are many factors to consider when thinking about weighting.

Still wondering what ballast options are best for you? Use our buoyancy tool below to determine what kind of ballast will best suit your needs.

Did we miss anything? Do you have any questions? Please feel free to comment below!!

Click here to read more on how to figure out if you are correctly weighted: Are you over-weighted too? How much weight do I need for scuba diving?

Air Sharing: Why Your SCUBA Configuration Matters

By Carlos Sagaro

You're on a relaxing dive enjoying the beauty of the underwater world. You’ve left all your frustration and responsibilities above the surface. After all, this is where you come to “get away from it all,” right??

Scared Diver Small

All of the sudden, you notice that another diver is swimming over to you wide-eyed and in a hurry. They give you the “out of air” hand signal just as they take their regulator out of their mouth.

This is where all your training and the choices you’ve made about how you configure your gear come into play.

How will you deal with this scenario? Is the way you’ll handle it optimal? Can you go through the motions in your mind’s eye right now and feel confident you are ready to handle an exasperated out-of-air diver?

When it comes to sharing air, there are many different configurations that divers use.

If you’ve ever wondered why different divers configure their primary regulator and their octopus different ways, and what the pros and cons are of each configuration, you’re going to want to read on because in this article we are going to touch on exactly that!

Disclaimer: Before beginning our discussion on air sharing techniques and configurations, it’s important to note that air sharing, especially in an emergency, is a skill that must be mastered in confined water under the supervision of a qualified SCUBA instructor. Do NOT SWITCH YOUR CURRENT CONFIGURATION without proper training and coaching from a qualified SCUBA instructor!

The origins of air sharing

When SCUBA diving was still new and considered by some to be an “extreme” sport, the gear that was used wasn’t nearly as advanced as it is today.

Early SCUBA rigs only had one primary regulator to breathe from. If your buddy ran out of air underwater, the only option was to share your only regulator by passing it back and forth between you and your buddy. Essentially, you’d take turns taking breaths from a single regulator.

Air Sharing Small

As SCUBA equipment became more advanced a redundant second stage was added. This redundant second stage, which is commonly known as an octopus, could be given to an out-of-air diver independently. Now both the out-of-air diver and the diver donating the air supply could breathe simultaneously from the same tank.

With the ability to have 2 divers breathing from the same tank come many questions about how to best configure your gear. The first question being….

Which regulator should you give a diver in distress?

Before we can address the issue of how to configure your regulators, we need to discuss the major philosophical difference in opinion that many SCUBA instructors have.

Recreational Set Small

You see, some instructors believe that an out-of-air diver should always receive the regulator which the diver that’s doing the rescue is breathing from, also called the primary regulator.

Others believe the out-of-air diver should receive the octopus.

While there is not “right” answer here, let’s take a look at some of the pros and cons of each method.

Some of the pros of donating the primary regulator (the regulator the diver is breathing from) include:

  • The shared regulator is usually the higher performing regulator:  The out of air diver is likely to have a higher breathing rate because of the nervousness / anxiety cause from being out of air.
  • It puts the diver that is donating the air source in control of the situation:  This means that the diver who is less likely to be in a panicked state becomes the dive leader.
  • Because the regulator being shared is the one the diver is breathing from, it needs to be on a longer hose:  This allows for the octopus to be on a shorter hose and reduces the chances of it dangling along and getting caught on the reef.
  • This configuration is usually more streamlined.
  • If an out-of-air and panicked diver rips the functioning regulator out of your mouth, you can instinctively reach for your alternate regulator which is what you would breathe from under this scenario anyway.

The cons of donating the primary regulator in a buddy-breathing scenario include:

  • It requires more skill / training to share air in this manner then using an octopus for a distressed out-of-air buddy.
  • When using an air2 or other similar regulator that serves the dual purpose of an inflator and a secondary regulator, that secondary regulator may not be as high performing as the primary.
  • Because the out-of-air diver needs the diver donating the air to participate, it is more difficult to simply grab an octopus and begin breathing without the assistance of the diver with air: This will make it more difficult for the distressed diver to get to his or her much needed air.

Diving with an octopus to give out as the alternate air source is probably the most common configuration.

The pros of giving out the octopus to an out-of-air buddy include:

  • Because the donating diver does not need to actively give up his or her regulator, the person who is out of air can gain access to the gas without having to rely on the donating diver’s skill level or proficiency.
  • The diver that is donating the gas never has to take the regulator they are breathing from out of their mouth.

The cons of giving out the octopus to out-of-air buddy include:

  • Because the octopus is on a longer hose and is rarely used, it is more likely to dangle or get caught up on a reef or a wreck.
  • Because it can dangle behind a diver, if a leak or free flow occurs at the 2nd stage it can go unnoticed for far longer than it would with other configurations.
  • Many of the octopus regulators on the market are meant to be cheaper and thus have more breathing resistance. Giving a diver who may already be panicked because they ran out of air a poor performing regulator may aggregate their panic.

Now that we understand some of the pros and cons of using an octopus for an out-of-air diver vs. giving them the regulator you are already breathing from, let’s look at some of the different configurations.

Configurations where you give out the octopus to an out of air diver

The placement of the octopus holder should be somewhere in the “safety triangle”. This is an imaginary triangle that goes from your chin to your waist in front where the octopus can be easily accessed by both the diver and their buddy.

Having the Octopus on a holder

There are many different types of octo holders on the market. Each design has their benefits and drawbacks. The basic premise behind all octo-holders is the same.

Cotopus Holder

They must hold the octopus securely throughout the dive so that the regulator does not accidentally become dislodged and begin to dangle. They must also simultaneously be easy to deploy and come lose if it is needed for an emergency. (IMAGE of Octo holder)

Because of this dichotomy, many octo-holders fail and end up having a diver dangle their octo behind them damaging both the regulator and the reef.

BCD with integrated Octo-holder

Octo Pocket small 1

Some BCD manufactures have taken note of the issue of keeping the octopus nice and tidy while still making it easy to deploy in case of emergency.

To help solve the octopus dilemma, they’ve designed their BCD’s to hold the octopus for you.

Using a D-ring as an octo holder

Yet another creative way to solve the octopus dilemma is to curl it into the D-ring of a BCD.

While this solution is less likely to result in the regulator becoming loose and dangling behind the diver, it does take a bit of getting used to.

Also, it may seem awkward to have the curled-up hose dangling below the D-ring where the octopus is stowed.

Configurations where the primary air source is donated

Air 2 (Regulator Low-Pressure Inflator Combo)

One of the most common configurations where the primary air source is placed on a longer hose and donated is when a diver is using an Air2 or similar inflator / regulator combo.

There are several low-pressure inflator / regulator combos on the market, but the SCUBA Pro Air 2 was one of the first systems that gained widespread use.

IMG 20180305 154422

By combining the low-pressure inflator and the alternate air source into one, the diver effectively eliminates one hose from their SCUBA rig.

You also eliminate the possibility of having the octopus dangle because the hose used for the low-pressure inflator is typically much shorter than that of an octopus.

As mentioned before, the downside is that it requires the diver to be more involved in an out-of-air scenario because the must give out their primary regulator.

Because the hose on the Air2 is short, it makes it very awkward and less than ideal to be donated to another diver for air sharing.

Hogarthian set up (long hose tech diving set up)

The final configuration worth mentioning is one that was born in cave / technical diving but has been adopted by many recreational divers.

It is known as the Hogarthian rig named after Bill Hogarth Main.

Backplate Harness Small

The rig consists of the primary regulator being a longer hose (up to 7 ft) curled around the diver’s body. The octopus is worn on a necklace right under the diver’s neck.

In this configuration the octopus never comes off the necklace. In an emergency, the diver donates the longer hose and then switches to the octo.

Some advantages to this system include:

  • Most divers using this configuration opt to have 2 high performing regulators on your rig which eliminates the low performing octopus other divers use..
  • It eliminates the possibility of a regulator ever dangling because it’s nearly impossible for the octopus to come loose from the necklace..
  • If a diver ever approaches you in an out of air scenario, you can give away your primary and have almost instant access to your back up.
  • Because this set up often uses a much longer hose, it will give you the freedom to have some more space to move should you ever have to share air.

The only real downside to this configuration is that it does require training and practice in sharing air using this configuration. Also, if using a long hose for the primary, it does require extra care to not drag the primary regulator on the floor since it is on a very long hose.

Below is a Video where we discuss Air Sharing in Different SCUBA Configurations:

What configuration do you use and why? let us know in the comments below.

How outside pressure affects the diver's ear

Equalizing Your Ears: Preventing SCUBA Diving Ear Problems

By Carlos Sagaro

Have you ever had problems equalizing on a dive? Maybe your ears hurt underwater when you descend? If you’re unlucky, maybe you know the feeling all too well. If you’re extremely lucky however, maybe you haven’t experienced this yet. If there’s one thing that’s certain in diving, it’s that sooner or later you’ll have a dive where the dreaded ear equalization problems will creep up. That’s where this guide will come in handy.

In my sixteen years as an instructor, I have seen all kinds of students who have had difficulty with equalization. Hell, even I had some problems with this skill when I first started. After all, it is not natural for us to “pop” our ears.

The good news is that the vast majority of the time SCUBA diving ear problems are easily correctable. Things like being able to equalize one ear easily but not the other, being afraid to push too hard and having sinus congestion are just a few examples of the things that happen which you can easily overcome. Below we will explain how to stop your ears from hurting underwater so you can dive comfortably for years to come.

Why do my ears hurt underwater?

Before we get started, let’s talk about what causes the pain we feel when we descend. It all has to do with pressure.

As we descend into the water column the pressure surrounding us increases. That increase causes our ear drums to compress. This happens because the water pressure outside of our ear is greater than the air pressure inside of our ear.

How outside pressure affects the diver's ear

Equalization is the process whereby we equalize the air pressure in our inner ear to the pressure outside of our ear. We do this by pushing air from our sinuses to our inner ear through the Eustachian Tube, a thin tube that connects our inner ear to our sinuses.

Because the Eustachian Tube is so thin, it is easily compressed. Once compressed, it becomes extremely difficult to pass air through the tube. This makes it almost impossible to equalize and is the reason why we must equalize early and often when we begin our descent into the depths.

What happens if you do not equalize?

Have you ever wondered what would happen if you did not equalize or were unable to equalize? Well, there are a couple of things that can occur and they are not pleasant.

First, you could theoretically cause your eardrums to burst if you were able to stand the pain caused by not equalizing and were able to descend deep enough into the water column. This is unlikely since the pain alone would likely cause you to stop your descent. What could happen is that, once you feel pain in your ears, you would try too hard to equalize by pushing air too forcefully. This can cause too much air to go into your ears and possibly rupture your eardrum. Not very pleasant!

There are two things that can cause you to push too hard:

  • The first is, you do not equalize early and often. This causes the Eustachian Tube to close which forces you to push air harder through your sinuses. Forcing the air in this manner could cause your eardrums to burst. This is why you should stop descending immediately when you feel pain in your ears. Forcing air into your ears on descent when you feel pain can cause your eardrums to burst.
  • Secondly, you dive while congested. The congestion causes the air to not pass through the Eustachian Tube properly. Upon ascent, the air in your inner ear cannot escape which, if not handled correctly, could cause your eardrum to burst. This is called a reverse block. I would like to note that, in the event that you feel pain in your ears on ascent, you MUST NOT attempt to equalize. In this case, you need to slow your ascent to a crawl so that the air can slowly escape. The last thing you want is to have an ear drum pop.

 

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When to equalize when SCUBA diving?

When we equalize is as important as how we equalize. Equalization occurs early and often. Before you break the surface and begin your descent, you should begin to equalize. You should equalize every couple of feet as you descend to your dive site. If you do not equalize early and often and force yourself down, your eardrum can compress causing pain. The pressure can even seal your Eustachian Tube. This is known as the “trapdoor effect” and can be avoided by equalizing early and often

ears hurt underwater, SCUBA diving ear problems, valsalva

A good rule thumb here is to understand that, if you feel pain in your ears, you have waited too long to equalize. In the event that your feel pressure in your ears, stop your descent and ascend a few feet until the pain goes away and you can equalize. Once this happens, you are free to continue to descend to that wreck you are dying to see!

You should never equalize on ascent. The air in your ear needs to escape as the surrounding pressure decreases. Because of this, there is no need to add more air to your inner ear on ascent.

Remember that, due to your dive site’s topography, your actual depth may change while you are diving. Whenever you ascend a little to see that shark swimming at the top of the reef, you have to equalize again to check out the eel in the hole at the bottom!

How to equalize underwater

There are several different ear equalization techniques you can use for ear preasure relief. Which one is best for you truly depends on your physiology, how your sinuses are functioning on the day you are equalizing and simple preference. The good news is that there is something for everyone here. In my experience as an instructor for several years, I can tell you that I have never had a student who I was not able to teach how to equalize. While there are rare cases where people cannot equalize due to physiological problems, the vast majority of people are able to do so once properly trained.

The most common method of equalization is called the Valsalva maneuver. This is probably the one that you were taught in your dive class. The Valsalva maneuver is named after Italian anatomist Antonio Maria Valsalva, who was the first to document the technique.

You perform the Valsalva Maneuver by pinching your nose and gently pushing air to the back of your throat through the Eustachian tubes and into your inner ear. Here’s the thing, in order for you to complete this correctly you should be able to physically see a bulge forming on either side of your nose if you look down. Think of it as blowing up a balloon. A good way to practice this is to equalize in front of a mirror while watching your nose. You should be able to see the skin on your nose expand. It is important to remember that, while you do not want to blow too forcefully, you do need to apply enough force to feel your ears filling with air. Go ahead and try it now.
ears hurt underwater, SCUBA diving ear problems, valsalva

If the Valsalva maneuver does not work, do not worry!

There are several ear equalization techniques you can try. 

  • Turning your head from one side or the other while performing the Valsalva Maneuver helps
  • Swallowing while doing the Valsalva maneuver helps
  • A combination of the above can help as well.
  • Tilting you head back while attempting the VM helps too
  • The Valsalva maneuver while wiggling your jaw forward can assist as well
  • The Toynbee Maneuver and can be used in lieu of the Valsalva maneuver. You perform the Toynbee maneuver by swallowing with your mouth closed and your nose plugged. You do not have to blow out while doing this
  • The Frenzel Maneuver is another alternative to the Valsalva maneuver. It is performed by pinching your nose while pressing your tongue against the back of your throat while making a “T” or “D” sound.

What you are doing with the vast majority of the variations above is relieving pressure on the Eustachian tubes to allow the air to enter them so you could equalize.

What if I still Can't Equalize Ear Pressure??

Believe it or not, despite all the variations you saw above, there is still a very small percentage of people who have difficulty equalizing. If you are one of these people, keep reading for some other tips to help you get to that dive site you’ve always wanted to see!

  • Descending feet first: If you have trouble equalizing, try descending feet-first rather than doing a head-first descent. This reduces the change in surrounding pressure drastically. Remember that the greatest pressure change occurs in the first 33 feet (10 meters) of water. By starting your descent feet-first, you reduce the dramatic nature of the pressure change increasing your chances of equalizing.
ears hurt underwater, SCUBA diving ear problems, valsalva

Diver Equalizing While Descending Feet First

  • Descending on a line: If you’re still having difficulty equalizing, you can control your descent even further by descending feet-first on a line. The trick is to go slowly and equalize early and often.
ears hurt underwater, SCUBA diving ear problems, valsalva

  • Chewing gum: Chewing gum before your dive relaxes your soft palate which has been known to assist in equalization. That being said, DO NOT chew gum during your dive! Besides the fact that chewing gum with a mouthpiece on is difficult. When you dive you’re breathing through your mouth which could cause you to choke on your gum. This could cause a potentially dangerous situation, so do not do it!

Congestion and diving

When you are congested or have a cold, it is not recommended that you dive. Congestion can make it extremely difficult to impossible to equalize. Also, as mentioned above,diving while congested could cause a reverse block, that’s where the air in your inner ear cannot escape and could potentially cause your eardrum to burst.

Some people have advocated taking medication to relieve congestion before a dive. This is potentially dangerous as the side effects of medications while under pressure are not completely understood and their effects could wear off mid-dive causing a dangerous situation.

The big takeaway here is that, when done properly, equalization is not difficult and it is safe. Just like anything else we try to do, it requires practice to master. Whichever method you decide on using, just remember that you will get better at it as you continue to dive.

A couple of things to remember:

  • Equalize right before you begin your descent and continually all the way down to your dive site.
  • Remember that we never equalize on ascent.
  • If you feel pain in your ears on descent, stop and ascend until the pain is relieved before attempting to equalize.
  • If you have difficulty equalizing remember that it is easier to equalize when you descend feet-first.
  • Do not dive when you are congested.
  • Practice several methods of equalization, just because one doesn’t work does not mean a different one won’t.
  • Finally, remember that practice makes perfect.

If you would like to learn more about the medical aspects of equalization including some video on what happens to your ear drum when you equalize, click the link below:

If you would like to learn more about the valsalva maneuver along with the other equalization techniques mentioned in this article. Make sure to watch this video from Dr. Edmond Kay on how to resolve common SCUBA diving ear problems. 

Underwater Navigation: How to use a SCUBA Compass

By Carlos Sagaro

I remember when I first started SCUBA diving. My instructor told me I should always have an underwater compass with me when I go diving. He “went over” compass navigation in my basic SCUBA class but, by the time I received my certification, I had little more than a BASIC understanding of how to use a SCUBA compass. If you feel the same way I did, then read on because in this article we are going to go over the compass and how to use it as a SCUBA navigation device.

Parts of the Compass

The most commonly known SCUBA navigation device is the compass. All divers have one and should carry it with them whenever they go underwater. After all, we all know that there is no such thing as an underwater GPS for Divers! However, many of us, including myself when I first started, do not really know how to use the compass correctly to navigate underwater.

 

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Before we get into how to navigate underwater, I want to review the parts of the compass:

The Card:

This is the part of the compass that has the degrees (from 0 to 359 and the letters that determine direction

It rotates inside of a closed chamber that is full of liquid, which allows us to use it underwater.​

SCUBA navigation device, best underwater compass, underwater navigation
SCUBA navigation device, best underwater compass, underwater navigation

The Bezel:

This a rotating piece of plastic on the outside of the compass which can be moved around to help us read our heading

The Lubber Line:

This line is used to determine the direction you are heading in.  It is fixed on the compass' face.

SCUBA navigation device, best underwater compass, underwater navigation
Window 1

The Side Window

This is a window on the side of the compass that makes it easier for us to see our heading when we are pointing the compass.

    It is important that you become familiar with the different parts of the compass and how to use them before you attempt to use a compass to navigate. Not doing so can cause you to get lost, which I am sure you do not want to have happen! **Note that a digital compass does not have all these parts**

    How to Use a Compass for Underwater Navigation

    The first thing we need to go over is how to hold your compass when underwater. This is important because different compasses are mounted in different ways. Determining what the best underwater compass for you to use is a personal preference but, it is important for you to understand how to hold them so you get the correct heading. Not knowing how to hold a compass can cause you to get an incorrect heading

    Hand-held compass

    When diving with a hand-held or pocket compass, you must hold the compass in front of you, with both hands and in a center line to your body when getting a heading. This will ensure that you are not off center and will allow the card to move freely

    SCUBA navigation device, best underwater compass, underwater navigation

    Wrist-mounted compass

    When using a wrist-mounted compass or a digital compass that is incorporated into a dive computer, you must hold the hand the compass is not mounted on in front of you pointing in the direction that you want to go while grabbing the arm that is pointing ahead in a ninety degree angle so that the wrist that the compass is mounted on goes across your body. This provides you with a fixed position for your compass and ensures that the card does not become stuck so you can get an accurate reading.

    Console-mounted compass

    This works just like the hand-held compass. The major difference is that you will hold the console the compass is attached to in front of you rather than just the compass. One thing that you need to be aware of is that often times compasses that are attached to consoles are placed there at an angle. This is done to allow the diver to have access to the window at the bottom of the compass. You must make sure you are holding your console in an orientation that allows the card to be free to move so that you can get an accurate reading.

    SCUBA navigation device, best underwater compass, underwater navigation

    Taking a heading

    A heading is the numerical description attached to the direction you are traveling in. This will always be between 0 and 360. It is common knows as degrees.

    Now that you know how to hold your compass, the next thing you need to be able to do is take a heading. You will take your heading by pointing the compass in the direction you are travelling in. The lubber line is fixed and will always point forward. The card will rotate in a manner that will always have the “N” pointing north. When you look through the window you will see a number, that number is your heading.

    If you would like to learn more about taking a heading, check out or video below.  In it we go over this as well as a few other aspects of compass navigation.

    How do I get back to where I am came from underwater?

    Introducing The Reciprocal course

    This is a very common question. Because we take headings in a circle from 0 to 360 degrees, it is possible to calculate your reciprocal, or opposite heading. To do this we use something called the add/subtract 180 rule. It requires a little math, but it is not difficult.

    Before I explain this, I want to point out that it is not uncommon for people to round either up or down when they take headings to make their calculations easier and there is nothing wrong with you doing that when you are calculating your headings.

    How this rule works is simple: If your heading is above 180 or higher, you subtract 180 to get your reciprocal heading. If your heading is below 179, you add 180 to get your reciprocal course.

    Example 1: Subtract 180

    You are heading 240 degrees west-southwest. In order for you to calculate your reciprocal course, you would subtract 180 degrees from that heading. 240 – 180 = 60 degrees east-northeast.

    Example 2: Add 180

    You are heading 160 degrees east-southeast. In order for you to calculate your reciprocal course, you would add 180 degrees from that heading. 160 + 180 = 340 degrees west-northwest.

     

    Feeling Lost During Your Dive Sucks! 

    thinpaperback 8 navigation tools

    Discover The 8 Little-Known Tools You NEED To Take With You On Every Dive To Avoid Being Lost!  ( FREE GUIDE )

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    How about natural navigation? How to use your compass to assist in natural navigation.

    SCUBA navigation device, best underwater compass, underwater navigation

    It is a very good idea to use your compass in conjunction with natural navigation. This is a very good way of avoiding tunnel vision, this is when you are so singular focused on your compass that you do not notice what is happening around you. I have seen it happen more than once that a student will focus so diligently on their compass that they will swim right passed the ascent line of the boat without even noticing it.

    By fixing your heading on something on the sea floor. A part of the reef or some other fixed object, you can focus on that object and your surroundings and then fix your heading on another object to continue swimming in your desired direction. This also allows you to continue to enjoy your dive. 

    What if there is a cross current?

    There are times when you will be swimming with a current coming across your body rather than in front or behind you. The idea here is to slightly deviate your swimming directing into to current to compensate. Of course, this is not an exact science, but it will allow you to compensate for the current and get you closer to your desired destination.

    Is the compass the primary / only navigational tool I need?

    Great question! While the compass is what is often emphasized in most beginner SCUBA courses it is not the only navigational tool, nor is it the only way to navigate underwater. Natural Navigation (using the environment itself as a navigational tool) is actually the type of navigation used most often. The reason why compass navigation is emphasized over Natural Navigation is two-fold.

    The first reason why compass navigation is prioritized is because it is incredibly important for performing boat checks. A boat check is what you do when you are unsure of your position underwater (more on that in a moment). During a boat check you ascend to the surface take the bearing on where the boat you need to return to is, and then descend back underwater to follow the heading which you took on the surface. This skill is critical to ensuring you make it back to the dive boat safely. This is why it is critical that you learn how to read and use the compass.

    The second reason why compass navigation is prioritized in most SCUBA classes is because it generally is easier and simpler to teach.

    So how do I perform a boat check using my compass?

    SCUBA navigation device, best underwater compass, underwater navigation

    The boat check is usually only done on shallow reefs. if you ever feel lost or unsure about your position on a reef, provided that there is not a strong current then you can perform a boat check.

    The idea is to go to the surface, take the heading of where the boat is, and then return underwater and swim in the direction of the boat. The reason for returning underwater is because by doing so you avoid stronger currents, waves and boats which are on the surface.

    To perform a boat check you'll need to follow these 6 simple steps:

    1. Ensure that there are no running boats in the area before ascending to perform a boat check. If you hear the sound of an engine, wait for it to go away. Sound travels 4 times faster underwater than it does on land so establishing where the sound is coming from is impossible while diving.
    2. Determine who will be the dive leader. This is the person who will be taking a bearing leading the group back to the boat.
    3. Ascend to the surface slowly to check for the position of the boat.
    4. Inflate your BCD and begin scanning the horizon for the dive boat. You may need to do a full circle sometimes before locating the dive boat.
    5. Once you've located the dive boat, point your compass in its direction and take note of the bearing by looking through the side window. You can use the bezel to lock in the reading you just took.
    6. Deflate your BCD and descend back to the reef / wreck.
    7. Swim back to the dive boat while following the heading that was taken on the surface.

    About dive leaders

    You probably remember from your entry level course that you should decide on a dive leader for the dive. This is especially true with compass navigation. The reason is because it is very easy for 2 different compasses to read slightly differently from each other. It's also very easy for 2 divers each paying attention to their own compass to become easily separated. For this reason it's incredibly important for just one person to be the dive leader and for that person to both follow the heading of the compass and continue to monitor their buddy and dive team while navigating underwater.

    How to Use Your Buddy To Take a Heading

    There are times when you are just going to have to do a boat check. Maybe you got turned around or you were busy paying attention to a turtle or other interesting sea creature.

    When your buddy ascends to do a boat check you can use him or her to take a bearing so you can also get an idea on the direction of the boat.​

    It is important to remember that the person who ascends and takes the bearing is the one who will lead the group back.

    Another good idea is to double check what bearing your buddy took when they get back down.

    ​Click below to check out our video explaining how we do this.

    I hope this has helped you understand the ins and outs of using a compass as a SCUBA navigation device. Keep in mind that the compass is only one of 8 different tools you can use to help you to navigate. If you'd like to learn more about the other 7 tools you can do so by clicking here to get our FREE guide "The 8 Navigational Tools You Should Never Dive Without"

    Scuba Diver removes her mask underwater

    Increasing your comfort underwater: One little-known drill that boosts your confidence like crazy!

    By Jose Cernuda

    Scuba Diver removes her mask underwater

    Scuba Diver removes her mask underwater

    You’re on a dive in 65 feet (that’s about 30 meters for my non-American friends) and your regulator begins to free flow. What you do next could be the difference between a cools story and a trip to a hyperbaric chamber

     

    Without going into what the proper procedure would be (I’ll leave that to the training agencies) how comfortable would do you think you’d be with this situation? Unless it’s something that you feel would be a minor annoyance, you might want to read on to learn a simple drill you could do to help you deal with this potentially dangerous situation.

    One of the most important attributes you can have as a diver is to be both comfortable and confident while underwater. Unfortunately, this is one of the toughest things to “teach” in a rushed SCUBA course.  There really are two reasons why this particular situation is hard to teach.  First, most dive courses barely have enough time to cover the basics, much less deal with events like these.  Second, being that this is a situation that is much more about mental state than anything else, it is hard to mimic.

    One of the best ways that I have seen my students become comfortable underwater over the years is by mastering skills which require them to hold their breath. The reason why breath-held skills increase your comfort on SCUBA is simple, if you know you can handle tasks which require you not to breathe for more than a few seconds, then any situation which can happen on a SCUBA unit becomes trivial because, for the most part, you’ll always have air when you’re on SCUBA. Even in the event of a worst case scenario, an out of air situation, you’ll still know you have plenty of time to figure out what to do and execute it so you can come out virtually unscathed.

    The Skin Diving Bailout

    So, just what is a Skin Diving Bailout anyway?  The skill is actually quite simple to complete and does not require SCUBA gear.   This skill should be done in shallow water, 4 or 5 feet (1.5 meters) is plenty.

    A skin diving bail out is when you immerse yourself into the water with your mask and fins off. You can wear a weight belt for this skill, just make sure you do a buoyancy check and are properly weighted.

    • You begin by sitting on the edge of the pool with your mask and fins in your hands.
    • You then immerse yourself into the water while holding your breath.
    • Once you are underwater, you place your fins on your feet.
    • Then you put your mask on and clear it,
    • After your mask is clear, you come to the surface and blast your snorkel. You should be able to continue breathing through your snorkel at the end of the skin diving bail out while keeping your head in the water.

    The key to mastering this skill is to take your time doing it. Make sure you breathe slowly and deeply before jumping in the water. Take a deep breath just before you jump in the water. 

    Now stay calm! Slowly put your fins on, put your mask on, clear it and finally clear your snorkel.    Staying calm and taking your time is key!  You’ll be amazed at how much easier it is to complete this skill when you take your time.  Rushing usually will just make you feel anxious and have you run out of air much sooner.  Be deliberate in your movements.  When it comes to this skill, fast is slow!

    This is the real takeaway, whatever happens underwater can be handled.  The key is staying calm, and acting slowly and deliberately.  Watch the video below to see how I do a skin diving bail out.

    Have you ever done a skin diving bail before? If so, what was your experience with it? I’d love to know in the comments below.