The Diver’s Guide to Choosing the Perfect SCUBA Wetsuit

By Carlos Sagaro

SCUBA wetsuits are an essential piece of gear that you need to be familiar with. Choosing the right wetsuit could mean the difference between having a pleasurable dive or being downright miserable. In this article, we’ll go over everything you need to know about choosing a wetsuit that’s right for you.

What is a SCUBA wetsuit?

Simply put, a wetsuit is a suit you wear while SCUBA diving that provides protection from the elements as well as keeping you warm.

Wetsuits are used by divers all around the world in all types of environments.  They come in several thicknesses designed to prevent heat loss and can be used in a variety of water temperatures (more on this later).  They are an essential piece of equipment that every SCUBA diver needs to be familiar with.

Divers in the water with Wetsuits

How do SCUBA wetsuits work?

As divers, we are taught that water conducts heat 25 times faster than air.  Because of this, we need to find a way to provide thermal protection in the water, so we do not go into hypothermia when diving.  They work by trapping a layer of water between your body and the suit.  The suit has seals in the arms, legs, and neck which trap a thin layer of water between your skin and the.  The water in the suit is heated by your body heat.  This prevents you from losing heat in the water.  While no wetsuit can completely reduce the loss of body heat in the water, they help significantly. 

Diver in thick wetsuit with gloves
Diver in thick wetsuit with gloves

Wetsuits for SCUBA also provide protection from the underwater environment.  We know that we are not supposed to touch anything while underwater.  While good buoyancy and training can help ensure that we “only leave bubbles and only take memories,” both current and surge can cause divers to accidentally come in contact with reefs or wrecks.  They provide protection for the diver should he or she accidentally touch a reef, wreck, or a stinging creature like a jellyfish, man-o-war, or fire coral.

In addition to thermal and exposure protection wetsuits also help shield your skin from the sun. Because the neoprene that wetsuits are made from is impermeable by UV rays they help to protect divers from getting sunburned both underwater and while on the surface.

Do you need a wetsuit to SCUBA dive?

The answer here is “maybe.”  It is certainly possible to dive without a wetsuit in warmer climates and many divers do.  However, diving without some sort of exposure or thermal protection is not recommended. 

In the end, we do not have total control over what might happen to us when we are underwater.  An unexpected current change or surge can cause us to bump into a reef or wreck.  A rogue jelly could swim right past you and you might miss it as you are looking in the other direction.  Even the warmest of water can cause discomfort or even hypothermia should a person stay in for too long. For these reasons alone, it is a good idea to dive with a wetsuit. 

How to Choose a SCUBA Diving Wetsuit

Before you do anything else, you need to make sure that the wetsuit you are buying is a SCUBA diving wetsuit.  This is important because diving wetsuits are designed to counteract the effects of pressure.  The neoprene used for SCUBA diving wetsuits has been designed to resist compression.  This is essential as, the deeper you go, the more the pressure around you rises.  If your suit compresses, it will not insulate as well as it should.  This is why you must choose a wetsuit that is designed for SCUBA diving rather than one designed for surfing or water-skiing.

Divers in different types of SCUBA Wetsuits

Types of Wetsuits

The next thing you need to think about is the type of wetsuit you are going to need.  There are several different types and we will go over them and their pros and cons below.

Shorty Wetsuits 

Diver in a Shorty Wetsuit

Full Wetsuits

They have long sleeves that cut off at the wrists and legs that cut off at the ankle.  They are more common amongst divers and provide more exposure and thermal protection than short suits.  We recommend that you choose a full suit for SCUBA diving rather than a shorty.

Diver sin Full SCUBA Wetsuits

Long Johns/Farmer John Wetsuit


 The benefit to long johns is that they can provide more thermal protection at your torso which is the part of the body that can lose more body heat.  Long Johns provide layering.  This will provide extra warmth should a dive require it.

Rash Guards

A rash guard is a dive skin that provides little to no thermal protection.  Rash guards are used to protect from the environment.  They are a good choice for divers who dive in warm waters but still want exposure protection.  They are nowhere near as thick as wetsuits so they do not protect as much as a wetsuit will.

Diver in a rash guard/ dive skin

Semi-Dry Wetsuit


Wetsuit Fit

First and foremost, our body types are all very different and this causes suits to be cut very differently.  You absolutely must try on any wetsuit that you are interested in.  Manufacturers have sizing charts on their websites which can be used as a guide.  I can tell you from personal experience over several years of buying wetsuits that no two fit alike.  Wetsuit design plays a huge factor in this as well.

Because manufacturers have different designs, a medium in one company may fit well but be way too tight in another company’s cut.  If you do not feel comfortable in your wetsuit, you’re going to have a terrible time underwater.  Be particular about your search before you pull the trigger on something you may regret buying later.  Another thing to consider is that suits are built different for men and women.  Due to the shape of male and female bodies, suits are cut in different ways.

Below is a checklist of things to consider when buying a suit.  While not an exhaustive list, this will help guide you through the process and help you determine whether or not a suit fits properly:

  • The wetsuit should fit snuggly without causing suffocation.
    • A loose suit will not provide thermal protection
  • There should be no excess room anywhere on your body
  • You should be able to squat down
  • You should be able to move your arms.
    • Thicker wetsuits will make this more difficult, but it still should be possible.
  • All the seals should be snug but not causing circulation or breathing issues.
  • The suit should allow for a comfortable range of motion and freedom of movement.
  • Price plays a factor in the durability of wetsuits.

Wetsuit Thickness

Diving Wetsuits come in different thicknesses.  The most common are .5 mm, 1-6 mm, and 7 mm+.  (MM stands for millimeter, the most common method to measure thickness) How thick your suit should be is dependent on two factors.  First, the temperature of the water that you are going to be diving in.  Second, your personal cold-water tolerance.  Colder waters require thicker suits than warm waters.

Diver in semit-dry wetsuit in cold water
Diver in semit-dry wetsuit in cold water

Divers in colder waters will wear thicker wetsuits

I want to discuss the second factor now.  Not everyone has the same tolerance for cold water.  Personally, I do not like to feel cold when I dive.  I do everything that I can to ensure that I do not feel cold when I am in the water.  As a result, I always dive 3mm suit at the minimum. 

The majority of my diving is in tropical waters.  A 3mm suit can be overkill on certain days, but I am okay with that.  If I feel overheated underwater, I just break the seal around my neck which lets water into the suit and cools me down immediately. 

There is one fact about temperature and diving when it comes to wetsuit usage.  You can always cool down underwater, but it is impossible to get warm once you are feeling cold.  If you feel overheated on a dive, all you need to do is gently pull the neck seal on your suit.  This will allow fresh water to enter the suit and will cool your body temperature.  If this is not enough, you can unzip your suit which will allow a more consistent flow of water into the suit.

Below is a chart that provides some guidance on wetsuit thickness relative to water temperature.  Please remember that this is just a guide and your level of comfort may require a thicker or thinner suit.

Wetsuit temperature guide

Water Temperature

Divers who Tend to Feel Warm

Divers Who Tend to Get Cold Easily

85 Degrees F or More

(29.4 C or More)

Swim Suit or Dive Skin

2 mm or less

80 - 84 Degrees F

(26.7 - 28.9 C)

2 mm

2 - 3 mm

74 - 79 Degrees F

(23.3 - 26.1 C)

2 - 3 mm

2 - 3 mm

3 mm + hood - 5 mm 

65 - 73 Degrees F

(18.3 - 22.8 C)

3 - 5 mm + Hood

5 - 7mm + hood

50 - 64 Degrees F

(10 - 17.7 C)

7mm Wetsuit - Semi-Drysuit + Hood

Dry Suit with Appropriate Undergarment + Hood

Below 50 Degrees F

(Below 10 Degrees C) 

Semi Dry or Dry Suit with Appropriate Undergarment + Hood

 Dry Suit with Appropriate Undergarment + Hood But This May Still not be Enough

Diving Wetsuit Materials

Wetsuits are made of neoprene.  Neoprene is a synthetic rubber material that is highly flexible and insulating.  The material has millions of tiny bubbles that trap air.  It is important to note that less expensive or poorly made suits have neoprene that is more prone to compression.  This is important for two reasons:  First, when neoprene compresses, it loses some of its insulating properties.  Second, neoprene is buoyant, and it loses some of its positive buoyancy when it compresses at depth. (we will delve further into this later in the article) Another factor to consider is durability.  Less expensive wetsuits are not as durable as more expensive suits.

There are two main types of neoprene for wetsuits and we will go over them here.

Open-Cell Neoprene

This type of neoprene is form-fitting and more porous.  It will require some form of lubrication to put on. A low pH shampoo or conditioner is often recommended.  This type of neoprene is much more fragile than the closed-cell neoprene.  It will require care when putting on and taking off as it can easily tear.  It is however less abrasive and more insulating than closed cell neoprene.  Open-cell neoprene is also more expensive than closed cell neoprene.

Closed-Cell Neoprene

The majority of wetsuits are made of closed-cell neoprene.  These suits are much more durable and last a lot longer than the open-cell type.  They are significantly easier to put on and take off.  They do not require lubrication to doff and don.  They are not as flexible as the open cell suits.  They are also less expensive.

Proprietary liners

Many wetsuit manufacturers have proprietary liners that they add to their suits.  The suits with this type of lining tend to be more expensive.  Regardless of the name the manufacturer gives the liner, the purpose is almost always the same.  The liners are designed to keep you warmer underwater.  The liners tend to make the suits less flexible than suits that are not lined.

SCUBA Wetsuit With Liner

There is nothing wrong with buying a wetsuit with a liner and the liners tend to make the suits warm and comfortable.  Which you purchase is up to you.  Always remember that fit is the priority.  Regardless of the cost of your suit or what liner it proclaims to have, it will be useless if it does not fit properly.

Wetsuit Seals

When we talk about seals, we refer to how the stitching is sealed on the suit itself.  There are a few different types of wetsuit seals used along the seams of the suits and we will go over them in this section.

Overlock Stitching

This type of stitch in on the inside of the wetsuit.  It is the most porous of all the stitching and can cause chaffing due to the fact that the stitch is not protected.  While effective, it should be used in warmer water because it allows seepage into the suit along the seams which will negatively affect the suit’s ability to maintain warmth.

Flatlock Stitch

This stitching rests on the outside of the wetsuit.  This is beneficial because the stitching on the interior of the suit seems flat and is less likely to chaff and makes it more comfortable.  However, this stitching is still quite porous and will allow for seepage.  As a result, this type of stitching is better for warm water diving. 

Blind Stitch

This is an excellent choice for wetsuits.  The material is first glued together then stitched. This allows for little to no seepage. 

There are a few different types of blind stitches.

  • Double-Blind stitch: Here a layer of stitching is added to the outside of the suit as well.  This provides another layer of protection and makes it much less likely for the seams to fail.
  • Blind Stitching with seal: This is sealed with a type of sealing solution of tape.  This makes water seepage practically zero and is ideal for cold-water wetsuit diving.

Wetsuit Zippers

Rear Zipper Suit