Drysuit Diver in the Water

Exposure protection - making decisions on your diving Part 1

David Mansfield

One of the most important aspects of being a good diver is selecting the proper exposure protection. The more comfortable a diver, the more control over unneeded stress from the environment and the potential for hypothermia or heat exhaustion. When a diver first starts scuba diving, they find themselves bombarded with hundreds of products and styles. Additionally, the diver is influenced by their instructor, dive buddies and even the professional staff of the dive store. Choices become hard as divers find themselves making a decision on a wetsuit or drysuit that they have never worn in the water! 

In the first part of this two-part series, we'll talk about some of the features and benefits of the current wetsuits on the market. 

A wetsuit is designed to allow water close to your body. Your body is constantly producing heat. A proper fitting wetsuit will 'trap' that water and allow your body to heat it up, thus giving you protection from the elements in terms of warmth. Obviously, exposure protection is a two-part theory in itself. Exposed skin is susceptible to advanced cooling because water wicks body heat away up to 25 times faster than air and anything exposed could come into contact with an ocean organism that stings or creates some sort of skin irritation known as contact dermatitis. 

The game for a wetsuit manufacturer is to figure out ways to control that water movement in your suit and create a higher degree of warmth. This will add to the overall quality of the wetsuit and allow a manufacturer to have better technological advances than a competitor. Here are some general ideas when selecting a wetsuit.

Diver on a wreck


You'll need to ask yourself three questions.

1. What's the water temperature where I dive and is there a thermocline?

This is one of the most important questions. If the average temperature of the dive site is 82° degrees F, you may not need a 7mm wetsuit to stay comfortable and you could experience overheating while diving. For those divers that dive in areas with a thermocline, they will be interested in knowing the bottom temperature because it wouldn't make sense to have a 3mm wetsuit that does little for you when the temperature at 60ft goes below 60° degrees F! 

2. What are other divers wearing?

A very hard habit for most of us is being observant. If you are in the tropics, you may find yourself looking a little silly while you put your drysuit on with Artic undergarments. Prior to your trip, you can get on social media or call a local dive shop to ask them what they wear at the dive site. This will give you a good idea on what you will need to dive. 

3. How much cold or warmth can I personally take?

You may go to a dive site and see a person with a shorty wetsuit next to a person with a 5mm full suit. This is because each of us have a differing tolerance level to cold and heat. Just because everyone else is doing something, doesn't always mean that you need to do it as well (you're welcome, Love Mom). If you have what I affectionately call Bio-Prene (commonly known as fat), you might actually be comfortable in a less thick wetsuit or find yourself not requiring hood and gloves because your body is utilizing and retaining heat differently than a person with little to no body fat. 

Typically, wetsuits range from .5mm (known as a skin) up to 8mm in the current industry standards. Generally speaking, greater than 75° can be .5mm - 4mm of protection, 65° - 75° would call for a 5mm or thicker while below 65° would call for a 7mm or greater. Anything colder and you'll be looking for a drysuit (don't worry, this is in Part 2!) to suit your needs. 

Wetsuit Diver

Select a high quality wetsuit when you are looking, you will own it for years!


A majority of wetsuits are pieces of cut neoprene. These pieces are glued together and then intricately stitched. This brings the material together in a fashion that allows for the minimum amount of water moving through the suit. For the user, the suit should allow water to seep in through the neoprene material and not through the stitching. This will create water movement that will accelerate the cooling of the body. One unique method of the stitching process is thermal sealing. This is when the pieces are glued, stitched and then laced with a thermal piece. It provides the strongest bond between the wetsuit pieces and also greatly minimizes water movement through the stitching design.

The key when you are looking for a wetsuit is to look at the quality of the stitching, the grade of the material (you can do this through touch) and also any warranties behind the suit. Companies will stand by the quality of their material and stitching when you purchase. 

Wetsuit Materials

An example of thermal sealing on a wetsuit.


Gaskets are an additive piece of material on a wetsuit. They are also designed to minimize water movement through the suit. These are typically found on the wrist and ankle entry points of a suit. They assist with the prevention of channeling or inadvertent flooding of the suit. If water is able to move into the suit freely, it will get up against your skin and give you a nice chill. Gaskets are there to help reduce that effort. Wetsuits like the Bare Evoke/Reactive and most semi-dry wetsuits will have this feature to reduce water intake.   

Wetsuit Gasket

An example of a gasket on a wetsuit. 

Internal materials

On most wetsuits, what you see on the outside is also what you see on the inside. As technology and knowledge improves, we're finding that the inner core of a wetsuit can also be manipulated to help increase warmth. The most advanced version of this knowledge is known as Celliant Infrared.  This takes your body heat and turns it into thermal energy that 'reflects' back to the body. This allows the diver to experience a greater amount of warmth while in the water. You'll also find manufacturers utilizing a material fleck (like titanium fleck) that provides this same kind of reflection on the trapped water in the suit. These technologies are there to keep you warm while you are in the water, but they also increase the price of your wetsuit. Though many of us should look at a suit as an investment as you will utilize it for years on some pretty cool dives ahead. Therefore, choosing this technology may put a minor strain on your pocketbook, but it will definitely make a great investment if you have a suit with superior materials for the next five to ten years. 

Celliant Technology

Celliant Infrared Technology in a wetsuit.

Proper Fit

We could talk for the next twenty years on the amazing technologies that come in a wetsuit, but none of these things will work properly if you do not have a proper fitting wetsuit. When you wear the wetsuit, it should fit you snugly. It should not be so tight that you have trouble breathing and it should not be loose at any point on your body. If the wetsuit is too snug, you'll experience an increased effect of this when you enter the water. If it's too loose, you will get rivers of chilly water flowing through your suit at unexpected times. This will eat away at your warmth index while you are in the water. 

In addition to the just perfect feeling of the suit, your wetsuit should stop at the wrist bone on the arms and right above the ankle on your legs. Since we are all built differently, you'll need to make a choice if it is too long or too short. You can get a custom fitting wetsuit or have a tailor that specializes in wetsuits make a minor adjustment for you on your investment. The key is that you are fitted properly and that you retain all of your flexibility inside the suit. Remember, the key is having a suit that keeps you warm; therefore, shop around and try multiple suits on before you purchase. You should never just hold a suit up to your body and think it will fit you perfectly. If you are making the investment, make sure you put it on and ensure it is properly fitting! 

Wetsuits are cut in an attempt to fit a majority of people in the world. For males, they range from Small to 5X-Large and for ladies they range from size 2 up to size 28 for most manufacturers. When you walk into the custom areas of a wetsuit, the sky is usually the limit. You'll be measured by the professional staff of the dive shop just like you would for a dress or suit from a seamstress. Those measurements would be remitted to the manufacturer to begin the building of your custom suit. 


Remember that a wetsuit is built to keep you warm in the environment you plan to dive. Selecting the right fitting suit with the features and benefits that fit your budget will create an opportunity for you to comfortably dive for years to come. Should you ever have questions, it doesn't hurt to seek out the advice of advanced divers or professionals that regularly dive. Just remember that the investment you make will be with you for a few years down the road. Ensure you research the product and utilize the key points of this article when you select your future wetsuit. 

For those of you interested in the benefits and features of a drysuit, we'll discuss those next month in Part two of Exposure Protection! 

About the Author:
D.J. Mansfield

D.J. Mansfield is a PADI Course Director who dives Southern California and has done so for 22 years. He is currently the Director of Operations for Beach Cities Scuba and is a committed ocean steward and trainer for divers all over the world.

Follow him on Instagram @djmansfield7or contact him at dj@beachcitiescuba.com.   

Did you know Beach Cities Scuba is a 100% AWARE partner? We are committed to supporting our ocean partners and creating a protected environment for sea life that includes responsible fishing practices and minimal human interaction. See how you can get involved today!

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