![]() However at a depth of about 15 metres (50 ft) of water, the thickness of the neoprene will be halved and its conductivity will be increased by about 50%, allowing heat to be lost at three times the rate at the surface. Uncompressed foam neoprene has a typical thermal conductivity in the region of 0.054 Wm −1K −1, which produces about twice the heat loss of still air, or one-tenth the loss of water. The result is that the gas-filled cavities restrict heat transfer to mostly conduction, which is partly through bubbles of entrapped gas, thereby greatly reducing heat transfer from the body (or from the layer of warmed water trapped between the body and the wetsuit) to the colder water surrounding the wetsuit. Nitrogen, like most gases, has very low thermal conductivity compared to water or to solids, and the small and enclosed nature of the gas bubbles minimizes heat transport through the gas by convection in the same way that cloth fabrics or feathers insulate by reducing convection of enclosed air spaces. Wetsuits are made of closed-cell foam neoprene, a synthetic rubber that contains small bubbles of nitrogen gas when made for use as wetsuit material (neoprene may also be manufactured without foaming for many other applications where insulating qualities are not important). Water has a thermal conductivity of 0.58 Wm −1K −1 while still air has a thermal conductivity of 0.024 Wm −1K −1, so an unprotected person can succumb to hypothermia even in warmish water on a warm day. Still water (without currents or convection) conducts heat away from the body by pure thermal diffusion, approximately 20 to 25 times more efficiently than still air. ![]() ![]() Semi-dry cuffs use a smooth surface to seal against the skin to reduce flushing. Wetsuits are used for thermal insulation for activities where the user is likely to be immersed in water, or frequently doused with heavy spray, often approaching from near-horizontal directions, where normal wet-weather clothing is unlikely to keep the water out.Īctivities include underwater diving, sailing, sea rescue operations, surfing, river rafting, whitewater kayaking and in some circumstances, endurance swimming. Secondary, and incidental, functions are buoyancy and protection from some environmental hazards such as abrasion, sunburn, and to a lesser extent, wind chill. The primary function of a wetsuit is thermal insulation to keep the wearer warm in conditions where they would otherwise lose body heat rapidly due to heat transfer by relatively large quantities of water. Dry suits are typically more expensive and more complex to use, but can be used where protection from lower temperatures or contaminated water is needed. Wetsuits can give adequate protection in warm to moderately cold waters. The difference between a wetsuit and a dry suit is that a wetsuit allows water to enter the suit, though good fit limits water circulation inside the suit, and between the inside and outside of the suit, while dry suits are designed to prevent water from entering, thus keeping the undergarments dry and preserving their insulating effectiveness. Suits range from a thin (2 mm or less) "shortie", covering just the torso, to a full 8 mm semi-dry, usually complemented by neoprene boots, gloves and hood. Further improvements in the seals at the neck, wrists, ankles and zippers produced a suit known as a "semi-dry".ĭifferent types of wetsuit are made for different uses and for different temperatures. Improvements in the way joints in the wetsuit were made by gluing, taping and blindstitching, helped the suit to remain waterproof and reduce flushing, the replacement of water trapped between suit and body by cold water from the outside. Wetsuits became available in the mid-1950s and evolved as the relatively fragile foamed neoprene was first backed, and later sandwiched, with thin sheets of tougher material such as nylon or later spandex (also known as lycra). Hugh Bradner, a University of California, Berkeley physicist, invented the modern wetsuit in 1952. The bubbles also give the wetsuit a low density, providing buoyancy in water. The insulation properties of neoprene foam depend mainly on bubbles of gas enclosed within the material, which reduce its ability to conduct heat. Its purpose is to provide thermal insulation and protection from abrasion, ultraviolet exposure, and stings from marine organisms. It is usually made of foamed neoprene, and is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports and other activities in or on water. Thermal protection for water-sport and underwater workĭiving suit, dry suit, hot water suit, rash guardĪ wetsuit is a garment worn to provide thermal protection while wet. Spring suit (shorty) and steamer (full suit) one-piece suits
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