Underwater Sports: Fin Swimming

The world record over 50 meters men's freestyle in conventional swimming stands at 21.64 seconds. By shaving off approximately 30%, one approaches the record marks over the same distance in men's fin swimming. Adding the crucial piece of equipment - the mono fin, a large fiber glass or plastic blade attached to both feet - converts conventional swimming into turbo-charged fin swimming.

Fin swimmers attempt to minimize their frontal resistance to the water by extending both arms in front and by keeping upper body motion to a minimum. Only the lower body and legs are kept in constant ondulating motion. A snorkel, braced over the athlete's forehead and nose, is used in addition to the mono fin for surface racing. Competitions are staged in pool and open water surface - athletes breath through their snorkels - and apnea - athletes hold their breath - events.

Some very basic rules apply for the surface events: one part of the swimmer, including his or her snorkel, must be at the surface at all times. However, athletes may swim completely submerged for up to 15 meters after turning at each end of the pool. The governing rules for fin swimming are authored by the World Underwater Federation - CMAS.