A wetsuit is a garment, usually made of foamed neoprene, which is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports, providing thermal insulation, abrasion resistance and buoyancy. The insulation properties depend on bubbles of gas enclosed within the material, which reduce its ability to conduct heat. The bubbles also give the wetsuit a low density, providing buoyancy in water.
Hugh Bradner, a University of California, Berkeley physicist invented the modern wetsuit in 1952. 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 Lycra/Spandex. 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.〔(【引用サイトリンク】url=http://www.ewetsuits.com/acatalog/How-Wetsuits-Work.html )〕 Further improvements in the seals at the neck, wrists and ankles produced a suit known as a "semi-dry".
Different types of wetsuit are made for different uses and for different temperatures. 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.
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 approacing from near-horizontal directions, where normal wet-weather clothing is unlikely to keep the water out.
Activities include underwater diving, sailing, sea rescue operations, surfing, river rafting, whitewater kayaking and in some circumstances, endurance swimming.
File:Decompression Dive-Preparation.JPG|alt=Two scuba divers in one-piece wetsuits and full scuba gear sitting in a boat, preparing to dive. Both divers are wearing tech rigs with back inflation BC and sling cylinders for decompression gas|Scuba divers in steamer wetsuits, one wearing a hood
File:wetsuit.jpg|alt= Kitesurfer wearing one-piece wetsuit, hanging from harness, separated from board. |One-piece suit worn by kitesurfer
File:RNLI Lifeguard Jersey.JPG|alt=RNLI crewman seated in small inflatable, wearing helmet and bright red wetsuit.|High visibility wetsuit worn by sea rescue personnel
File:Mikebaird - Two Surfing Teens.jpg|alt=Two surfers wearing one-piece wetsuits, riding a wave.|Surfers in steamer wetsuits
In open water swimming events the use of wetsuits is controversial, as some participants claim that wetsuits are being worn for competitive advantage and not just for warmth.〔Kent, Hazen (The Rap on Wetsuits in Triathlon ) trinewbies.com〕
Unlike triathlons, which allow swimmers to wear wetsuits when the water is below a certain temperature (the standard is at the surface or up to for unofficial events.〔http://triathlonwetsuitstore.com/at-what-temps-can-you-use-a-wetsuit/〕), most open water swim races either do not permit the use of wetsuits (usually defined as anything covering the body above the waist or below the knees), or put wetsuit-clad swimmers in a separate category and/or make them ineligible for race awards. This varies by locales and times of the year, where water temperatures are substantially below comfortable.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』