What is the longest Olympics swim race?
The longest swimmign race for men is the 1500 metres and the longest for women is the 800m that is in the pool.
The longest swimming race for men and for women is 10 kilometres in open water.
for swimming there is a meet called Olympic trials to reach that point there are tie standards you must reach. From that point the swimmers swim once in prelims where the top 16 move on to semi finals once the swimmers swim here the Field narrows even more down to 8 swimmers finally the swimmers swim one last race in the finals the top two swimmers in that race go to the Olympics
The Olympic triathlon consists of a 1.5 kilometer swim, followed by a 40km bike ride, and then a 10km run. After a mass start, the race remains continuous, with no stops in between the three legs. Therefore, fast transitions between legs are critical to a good race performance. * http://running.about.com/od/olympics/a/whatistriathlon.htm
If you are referring to competition pools, then your answer is Long Course Meters. This course, used in the Olympics, FINA World Championships, and US Summer Nationals, is 50 meters long. If you are referring to longest swimming competition, it's definitely open water swimming. The longest race held in the Olympics is the 25K.