Open water swimming, also called marathon swimming, is a swimming event conducted outdoors in natural water bodies like lakes, rivers and oceans. Most open water swimming races are held over a long-distance, and require high levels of endurance. The sport is currently practiced in almost all countries around the world.
Open water swimming has been an officially recognized sport for several decades and is part of the Olympic Games. Competitive races are conducted over various distances depending on the sanctioning body that conducts the race. At the Olympics, the race is over a distance of 10km. At the FINA World Championships, races are conducted for 5km, 10km, and 25km distances.
The races are fairly straightforward. Athletes start together from a starting point and the swimmer to first reach the end is declared the winner. A reason that the sport is sometimes referred to as marathon swimming is that the 10km event typically takes the elite swimmers around two hours to complete, about the same time as elite runners take to complete a running marathon.
Besides the use of common swimming equipment like goggles, swim caps, and swimsuits, one major aspect of open water swimming is the use of wetsuits. Its usage depends on the sanctioning body. Some competitions allow the usage of wetsuits while others consider racing with wetsuits as a different division.
The sport has steadily grown in popularity and besides the Olympics, there are several countries in which open water swim championships are conducted.
- Freestyle Swimming — in these events competitors can swim using any stroke of their choice.
- Swimming (General) - the sport of propelling oneself through water using the limbs.
- Open Water (Coastal) Rowing — a type of rowing performed on open water, requiring wider and more robust boats than those used on rivers and lakes.
- Ironman Surf lifesaving — combines four major aspects of surf-lifesaving into a single race, one of which is an open water swim.
- Marathon Swimming at the Olympics
- Marathon Swimming at the Commonwealth Games
- Marathon Swimming at the Asian Games
- Complete list of sports
- The Encyclopedia of Sports