It’s not such a simple question. Both wetsuits and drysuits are designed to keep you warm during and after diving. But each person does it in their own way. It mainly depends on what waters you dive in most often and what you personally are comfortable with.
Let’s take a look at what you should consider.
Drysuits: trilaminate vs. neoprene
For diving in colder water, a drysuit is indispensable. This is because water removes heat from the body about 20 times faster than air. And this is the main principle of a drysuit – there is an air gap between you and the cold water, not a thin layer of water like with neoprene.
When you dive in a drysuit, you stay perfectly dry inside. Your body heats the air in the suit, not the water, so you can stay cool for several hours in really cold water.
Trilaminate suits (made with several layers of material) are really just a waterproof shell. They don’t get very warm on their own, so you wear warm underwear underneath – sort of like functional thermal underwear for runners or skiers. The colder the water, the thicker the layer you need.
There are also dry suits made of neoprene that combine the comfort of a classic wetsuit with the benefits of a dry suit. Thanks to the insulating properties of neoprene, you don’t need such thick underwear and the suit follows the body better. It is more flexible and less “balloon-like”.
Unlike wet suits, which deliberately let some water in, dry suits have special rubber cuffs around the neck and wrists. These create a waterproof barrier. When they’re properly fitted, not a drop of water gets under the suit.
Neoprene
If you’re deciding between a dry suit and a wet suit, you’re probably diving in waters that are colder than the tropics. For milder conditions, a thicker wetsuit, such as 7 mm, is usually sufficient.
Good quality wetsuits work simply – a thin layer of water gets under the suit and warms your body. For this to work, the suit must fit perfectly. If it’s too loose, the cold water keeps flowing underneath and you’ll never get warm.
A well-fitting wetsuit is like a second skin. It squeezes you from all sides, but it’s flexible so you can move around in it. The more stretchy the material, the better you can move and the easier it is to get into – which you’ll especially appreciate when dressing on the boat or at the beach.
Semi-dry suit: the happy medium?
There is also a compromise between a dry suit and a wetsuit – the so-called semi-dry suit. It combines the close-fitting cut of a wetsuit with special features that restrict the flow of water under the suit. It usually has a waterproof zipper and sealing cuffs that minimize water exchange.
The advantage is that it doesn’t feel as restrictive as a dry suit, but it also keeps you warm better than a regular wetsuit. For many divers, this is the ideal choice for waters around 10-15°C.
What to choose?
The decision depends on three things: where you dive most often, how much you want to invest and what is more comfortable for you.
Dry suits are the most expensive (20-50k) but essential for really cold waters. Neoprene suits are more affordable (3-15 thousand CZK) and are enough for warmer seas. Semi-dry suits are somewhere in between (10-20 thousand CZK).
In terms of comfort – a wetsuit gives more freedom of movement, but after a longer dive you can freeze in it. A drysuit will keep you warm, but needs practice in donning and controlling buoyancy (the air in the suit floats you).
Regardless of which type you opt for, a quality suit is one of the most important investments in dive gear. If you get cold, no gorgeous coral reef will save you from cutting your dive short.