Home Tech Tips Alec Peirce Tech Tips: Dry Suits Part II

Alec Peirce Tech Tips: Dry Suits Part II

Alec Peirce dry suits
Alec Peirce dry suits

We are once again into the drysuit diving season.  I want to share information you need to intelligently shop for a drysuit. I have already shared one drysuit video in which I showed you an old drysuit from the 1960s. It was made of thin rubber, that was basically a garbage bag to keep you dry. Think back – two pieces included a jacket with an attached hood and a pair of pants you would roll together at the waist. This rubber would suit would be against your skin unless you were smart enough to put on a pair of long underwear or something else to keep you warm. Back in the 1960s, we didn’t have fleece or the warm undergarments we have these days so we used long underwear, sweaters and such. Invariably these “undergarments” of the day got soaked yet we still stayed relatively dry. Despite the first drysuits being very basic – no buoyancy or special boots – they allowed us to go scuba diving in cool water which was the whole idea.

By Alec Peirce

Dry suits today are very sophisticated but can be grouped into two different styles. Those two styles are based on the suits materials.  Within those two styles, there are different accessories and features. If you split drysuits down the middle, you have; neoprene and lightweight styles. There have been different names for them in the past but those have all gone by the wayside. 

After those first rubber drysuits, neoprene was created. Wetsuits are very popular, they are made from a foam neoprene. The neoprene keep you warm by trapping a thin layer of water against your body. Keep in mind that water does not go through the neoprene wetsuit, it travels up the ankles, down the neck, cuffs of the arms, through the seams, and so on. They are not intended to be totally waterproof – hence the term “wetsuit”. You can take that same foam neoprene and make a suit that is in fact completely waterproof. It will keep you completely dry but you must seal all the seams. If you take a look at the seams inside, sometimes outside too, you will find all the seams are sealed. Sometimes you will find a piece of tape running along the seams. You will also find special rubber seals around the wrist and neck. And most commonly around the ankles and feet there is an attached boot. The boot is neoprene and also sealed.

The original foam neoprene was 7 millimeters or ¼” inch thick and that suit did provide some warmth although you would want to wear pants and a t-shirt. As the water got colder, you add more or thicker underwear. This is no different than insulation inside a house: first is the drysuit, then your insulating underwear, then your body. Divers over the years used a variety of clothing to accommodate the cold. In the last few years more specialized drysuit underwear has been introduced. Foam neoprene does keep you warm but each style has its advantages and disadvantages, neither is perfect or there would only be one style.   Both lightweight and neoprene drysuits are available based on a person’s diving conditions.

Healthways skin suits
Healthways skin suits

Let’s take a look at the two styles. First, we look at the old fashioned 7 millimeter foam neoprene. Essentially, it is a one-piece wetsuit – but it is a drysuit and what makes it a drysuit is that we seal it with rubber at the neck and wrists etc.  The difference between a wetsuit and a neoprene drysuit is that it is sealed around you with a big zipper across the shoulders.  The neck has nylon inside to help pop your head through, the long piece of rubber at the wrist is then tucked in against the skin. We put air in our modern drysuits to create a better seal. The other difference is the boot molded onto the leg of the drysuit. The neoprene boot has additional rubber overtop to create added strength. The advantages of this particular style is that it keeps you warm.

These older neoprene drysuits are not as popular as they once where. The disadvantages are:  thicker and more buoyant so divers must add more weigh. The advantage is that these drysuits do keep you dry. It is nearly impossible to stay 100% dry in a drysuit – water leaks or condensation happens. Foam neoprene suits still keep you warm and mostly dry.  Let’s look at another style of neoprene drysuit that is lighter but with many of the same attributes. This type drysuit is called a crushed or compressed neoprene. It goes through a special process that takes 7 millimeters down to 4 millimeters thick which makes it thinner, less buoyant, lighter, stronger and less bulky. Nowadays you will most often find this crushed style in dive stores as it still keeps you warm even if water leaks in.

Now let’s take a look at the other style of suit – lightweight or laminated. This style of drysuit has a number of features. Look at the material – it is a thin, strong nylon mesh with PVC coating that is the same material as in most BCD’s. This makes the suit waterproof, it has a zipper across the chest – some people call it “self-donning” zipper which is a misnomer.  It has a rubber seal on the neck as well as at the wrists and molded boots.  Essentially the biggest difference is that type of material it is made of compared to a neoprene drysuit.

The advantages of this type of suit is that it is very lightweight and strong.  It can be rolled into a bundle the size of a wetsuit.   The disadvantage is it has no warmth.  If you take this lightweight suit into relatively warm water, say 75F, you will become cold quickly.  With this style you must wear warm underwear on every dive.  The suit itself has no warmth in it.  Another advantage is that you don’t need as many weights as the wetsuit style.   Neither suit style is perfect but each style depends on what works for each diver, body size and other factors.  So there you have the two basic styles with more information coming on dry suits.