A dry suit provides protection from water by sealing all covered body parts. It has an inflation valve for buoyancy adjustments and two types: membrane and neoprene. The former requires an undersuit for thermal protection, while the latter provides insulation and buoyancy. Some dry suits have built-in foot protection and a front zipper. The choice of suit depends on water temperature and the need for mobility.
As a type of diving suit, a dry suit is a garment designed to provide a layer of protection between the wearer’s skin and the surrounding water. Unlike a wet suit, which allows a small amount of water to accumulate in the suit, the dry suit effectively seals all covered body parts so that no water can enter the suit. This is achieved with a close fitting design that includes watertight seals at the wrists, neck and ankles of the drysuit. Often, these gaskets are made from latex, which will remain supple for about two years while maintaining the watertight seal.
One of the dry suit’s defining attributes is an inflation valve that will allow the wearer to make adjustments to the suit’s buoyancy. This is especially important, as the dry suit is often worn for deep sea scuba diving. As the diver descends, using the valve to inject gases that have been stored in a diving regulator regulates the pressure inside the suit. When the diver is ready to return to the surface, a vent valve on the suit allows the wearer to release gas from the suit. On some dry suits, the vent valve will operate automatically, while on others the user will need to operate the valve manually. In the event of a malfunction of the relief valve, the gas can be released during a climb by slightly loosening the neck or one of the wrist seals.
There are essentially two types of dry suits that are used frequently. The membrane dry suit is usually made from materials such as vulcanized rubber or a combination of nylon and butyl rubber. Membrane drysuits do not offer true thermal protection in colder waters. However, many divers will wear an undersuit with a membrane suit, which is what actually provides the thermal protection and also holds in gases for buoyancy. In warmer climates, the diver may choose to omit the undersuit, but this will affect the effectiveness of the gas released to create buoyancy. Membrane drysuits are relatively easy to put on and take off when needed.
Neoprene drysuits, on the other hand, provide a degree of thermal insulation and help maintain buoyancy. In general, the neoprene drysuit is often considered the better of the two options, as no undersuit is needed and the properties of neoprene make it less susceptible to loss of buoyancy should the suit become damaged or ruptured in some way. The neoprene dry suit is much stiffer than the membrane style and takes more time and effort to put on and take off.
While many types of drysuits come with ankle seals, there are models that also include built-in foot protection. Modern versions of the dry suit also tend to include a zipper which is usually found on the front of the suit or over the shoulders. Many divers find the front-zippered types easier to use and also more comfortable to wear. People who dive professionally often find that the neoprene drysuit is best suited in warmer waters, while the membrane drysuit is better for situations where the ability to move with a degree of freedom is more important.