How to choose a wetsuit

How to make the right choice of a wetsuit?

The wetsuit has become, in just a few decades, an indispensable piece of equipment for practicing underwater diving. Created by Georges Beuchat in 1953, this wetsuit is worn by scuba diving enthusiasts as well as snorkelers, spearfishers and freedivers and is used, above all, to protect against the cold.

Underwater, the body undergoes a direct transfer of heat from the skin to the water. The body cools down 25 times faster, which increases the need to wear a neoprene suit to delay cooling. The wetsuit will have to be adapted according to the water temperature, the depth and the duration of the dive. The wetsuit also protects the skin from external aggressions such as sudden impact with the bottom or contact with stinging animals (jellyfish).

What are the different types of wetsuits?

Neoprene wet suit

This type of wetsuit is undoubtedly the most widespread in the world. These wet suits offer an important thermal protection and are, moreover, versatile. Indeed, thanks to their flexibility, you can combine the layers to have different thicknesses according to the level of insulation you wish to achieve or use the different parts separately.

Some wetsuits allow you to put two layers on the chest for maximum thermal protection. Wetsuits keep the body warm even when wet. The small amount of water trapped between the skin and the neoprene warms up quickly when it comes in contact with a warm surface (our body's surface is 37.5°). The circulation of water, caused by movement, tends to replace the heated fluid, which will eventually cause the body to cool down. Neoprene is a material of the rubber family which is made of rubber polymer filled with air bubbles. Its interest lies in its great resistance to ozone, hydrocarbons but especially to sea water.

- It is suitable for use in water with a temperature above 15°C.

- The most affordable combinations.

- Adjustable and combinable according to diving conditions.

Semi-sealed suit

This type of suit is a hybrid between wet suits and dry suits. Made of 4 to 7 mm thick neoprene, the semi-waterproof suit insulates almost totally from water, partly thanks to its sleeves and its waterproof back closure. This thermal protection is less flexible than a wet suit, and the inability to inject air inside causes greater compression on the body depending on the depth.

- Suitable for water from 10 °C to 20 °C.

- Excellent compromise between the ease of use of the wet suit and the thermal comfort of a waterproof suit.

- Less water circulation and therefore better insulation than with wet suits.

- A one-piece suit.

- This suit requires less ballast.

- No training is required to use this suit.

Waterproof suit

This type of wetsuit is mainly used by experienced divers diving all year round in cold or even very cold water, but also by rebreather divers or technical divers who dive for several hours at a time. This wetsuit is the ultimate bulwark against water by completely isolating the body from the dangerous liquid. 

This type of wetsuit is available in three different models, the neoprene suit, the compressed neoprene suit, and the trilaminate suit composed of three different layers of fabric with a lower insulating power but with an increased resistance to tears. For each model, thermal protection is provided by the clothing you wear under your suit. For the trilaminate suit, several layers of clothing are recommended. This type of suit requires a different use than wet and semi-wet suits. 

An inflator is connected to the air cylinder via a pressure reducer to inject air into it. This mechanism prevents the garment from being crushed when the pressure increases during immersion. The injected gas forms a layer of air that serves as thermal insulation. Be careful, however, because this air has a real impact on your buoyancy. The gas circulates freely inside your suit and can become concentrated in your lower body causing an uncontrolled ascent with your feet upwards.

How to choose the thickness of your neoprene suit?

The principle is quite simple: the colder the water, the thicker your wetsuit should be. You can consult a temperature/thickness correspondence table which is given as an indication. Other external factors can influence these data such as your age, your body mass, your fatigue, the frequency of diving...

- Suitable for cold or very cold water.

- No water ingress.

- This combination requires less ballast.

- Training is required to learn the principles of buoyancy related to the use of air inside the suit.

- Probably the most expensive type of wetsuit.

Water temperature / Thickness

- Above 28 °C = jacket, top, shorty or even a 3 mm suit for the coldest.

- from 25 to 27 °C = 3 mm full suit

- from 21 to 25 °C = 5 mm integral combination

- from 17 to 20 °C = 7 mm full suit with hood and booties

- from 13 to 17 °C = 5 or 7 mm full suit with the addition of overcoat, shorty, hood and booties

- from 10 to 15 °C = semi-sealed suit with hood, slippers and gloves

- Below 10 °C = waterproof suit

Don't forget that you can complete your diving set with a pair of gloves, slippers and a hood. The latter is highly recommended when the water temperature is quite low (below 20°C). Indeed, a diver loses 80% of his body heat through his head.

Which size of wetsuit suits me best?

Finding the ideal wetsuit model is a little obstacle course, as there are so many models, ranges and brands to choose from. Be patient and above all try different wetsuits before you find what you are looking for. Under no circumstances should you take a suit that will serve you well on your neck and chest. You must be free to move freely.