A wetsuit, worn by divers, windsurfers, and others engaged in water sports, is a garment, made of foamed neoprene that provides thermal insulation, abrasion resistance, and buoyancy. The suit provides insulation through bubbles of gas enclosed within the material which reduces its ability to conduct heat. These bubbles also provide buoyancy in water. Contrary to popular belief the layer of warm water trapped between the suit and the skin provides very little thermal insulation.
Wetsuits first appeared in the early 1950s and evolved as the fragile neoprene was first backed then sandwiched with tougher material such as nylon. Through use of gluing, taping, and blindstitching the joints were improved and remained waterproof. Other improvements around the seals at the neck, wrists, and ankles produced a suit known as a “semi-dry”.
Wetsuits range in use and temperature tolerance. They can range form this to a full 8 mm. These suits take advantage of the fact that water is approximately 25 times more efficient at conducting heat away from the body. Wetsuits are made of closed-cell, foam neoprene, a synthetic rubber that contains nitrogen gas bubbles when made for use as wetsuit material. Nitrogen has low thermal conductivity in respect to water and solids. Some wetsuits use wool and titanium fibers that add a layer of gas cells in other ways while keeping the thickness of the suit to a minimum. These fabric layers trap heat in the gas cavities forcing it to travel slowly through the entrapped gas and reducing heat transfer from the body.
The suit must fit tightly to work properly; too loose a fit will allow water to escape from between the suit and the body, taking the body heat with it. The deeper one dives the more the suit loses buoyancy due to the pressure compressing the neoprene.
Hugh Bradner is considered the original inventor of the wetsuit when he had the insight that a thin layer of trapped water could be tolerated between the suit and the skin so long as trapped bubbles provided insulation. Dr. Bradner understood that the gas in the suit fabric provided the thermal insulation as opposed to the common theory that the water between the suit and skin provided insulation. He sent his initial ideas to Lauriston C. Marshal who was involved in a U.S. Navy/National Research Council Panel on Underwater swimmers. Willard Bascom, however, was the one to recommend using neoprene as a feasible material to Bradner.
Bradner and Bascom were unable to successfully market a version to the public. Their patent was rejected since the design was to similar to a flight suit. The navy also rejected the suits due to fears that the gas in the neoprene component of the suits might be detected by underwater sonar. Traditionally Jack O’Neill is credited with the invention of the wetsuit and the use of neoprene. O’Neill founded his self named company that manufactured wetsuits in 1952. Another neoprene company, Body Glove, was founded in 1953.
In Europe some swimsuits were made of sponge rubber. This lead to the production of the Heinke Dolphin Suit, in England, where it was made natural rubber lined with stockinet. Most original wetsuits were black although brightly colored ones showed up in the 1970s. The suits in the 80s had patches and logos sewn on. Originally two strips of rubber were overlapped and sewn together; however, this punctured holes into the suit allowing water to pass through. Stretching the foam also enlarged the needle holes causing the seams of the suit to be very cold. This also allowed the suit to tear easier at the seams when putting on or taking off the suit. Taping the seams became the solution to these early sewing problems. A strong nylon cloth with a thin waterproof backing was used as tape. The tape could be placed after sewing the suit and would provide extra strength to prevent tearing along the needle holes.
Early suits were fabricated by hand which led to sizing errors and possible leakage along the seams. Initial suits were sewn, glued, or taped. Then came sewing with tape, glue and tape, or perhaps all three. The blind stitch sewing machine solved the problem of the needle going through the neoprene since the curved needle just shallowly dipped in behind the fabric backing. Since blind stitching allowed the sheets to but up to the edge of the other sheet it quickly became the primary method for sewing wetsuits together.
In more modern suits lycra and spandex have mostly replaced the raw nylon backing. Lycra allows a lot of stretching without any damage to the suit. Recent developments have led to manufacturers combining various materials, like spandex, wool, and titanium, with neoprene to lend additional warmth or flexibility. These new developments along with precision computer-controlled cutting have led to a nearly leak free suit.
Wetsuits come in various thicknesses depending on the use. The thicker the suit the warmer it is; however, many divers choose to wear a thin layer even when the water is warm in order to have protection from jellyfish, coral, and sunburn. A thick suit is stiffer and can restrict mobility, so at a certain thickness a suit becomes impractical. Usually the suits have no feet or hood and the diver must wear separate pieces to cover the head and the feet. There are also specialized wetsuits for swimming long distance primarily used by those swimming in triathlons.
Heated wetsuits, with battery generated heat, are being tested and should be on the market soon.