Both male and female competitors, who are classified on their functional ability to perform each stroke, test their skills in freestyle, backstroke, butterfly, breaststroke and medley events.
Athletes can have a physical, visual or intellectual impairment. As a result the rules of the International Swimming Federation (FINA) are modified to include optional starting platforms and in-water starts for some athletes or the use of signals or “tappers” for those with visual impairments. No prostheses or assistive devices are permitted in the pool.
A FINA standard eight-lane 50m pool is required for competition at the Paralympic Games. Events are conducted as heats for eight competitors per class and with the fastest eight swimmers per class competing in the finals. There are various forms for swimmers to start their race; in the water, a dive start sitting on the starting platform or the typical standing start.
During a swimming event, swimmers who are blind are required to have an assistant to help him/her as he or she approaches the swimming pool end wall, either to make a turn or for the finish of the race. This process is called tapping and performed by a "tapper". These swimmers are also required to wear blackened goggles in all their events.
The clothing for swimmers is a bathing suit. It is forbidden for athletes to use anything that may aid the swimmers speed, buoyancy or endurance. Swimming caps and protective eye-goggles are permitted. The goggles protect the swimmers' eyes as well as improving their vision in the water.
Swimming has been part of the Paralympic programme since the first Games in Rome in 1960 and has seen the number of athletes and countries take part increase every four years since. The USA's Trischa Zorn is the sport's most decorated Paralympian having won 32 gold, 9 silver and 5 bronze medals between 1980 and 2004.
At the London 2012 Games 604 swimmers from 74 countries competed in 148 medal events.
World Championships are held every two years in addition to regional Championships. In July 2015, the Scottish city of Glasgow staged the IPC Swimming World Championships attracting over 580 athletes from nearly 70 countries who took part in 152 medal events.