The classification of the IOC
The international Olympic Committee (or IOC) shares the distance in swimming in two varieties: open and closed water, in other words, swimming in the sea or in the pool.
The open water swimming, or marathon, was included in the programme of competitions, most recently in 2008 in Beijing. This race is carried out on a 10 km Is the longest distance in open water.
Swimming in the pool is a more traditional discipline, and the longest distance in this area – 1500 m freestyle.
Russian official classification refers to the sailing and water sports, the term "swimming" is not used.
Competition in the pool
International competitions are held only in the basins, the length of which usually amounts to 50 or 100 m. Due to the fact that the athlete often changes direction, its speed of passage of the same distance is often slightly higher than if he followed a longer section without making turns. It had several problems with the fixation of the speed.
In 1908 it was decided that to capture records only in longer pools than the Olympics so the games were not put records in swimming. But in 1956, this decision was reversed, now the records can be put only in pools of 50 and 55 meters long. Since 1957, the registration records were begun again. In the period from 1988 to 1993, the decision was revised again, and now to set the records can be in the 25-meter pool.
Swimming in open water
The distance of 10 km in long-distance swimming is considered. Once it was the inheritance of single experimenters, and now swim for long distances were held EN masse.
History started long distance swimming in the XIX century, when the British Matthew Webb overcame Bay of the English channel by swimming in 1975. To do this, it took him 21 hours and 45 minutes.
Competitions in the open water was included in the FINA world Championships in 1991. Now, every even year since 2000, are the world Championships in open water swimming at distances of 5, 10 and 25 km But the longest Olympic distance open water swim is 10 km away.