The world record over 50 meters freestyle swimming stands at 20.94 seconds. Shave off about 30% and you get to the record marks in men’s fin swimming (50 M APNEA): 14.34! The formula applies to all other distances as well. Attaching the mono fin, a large fibre glass or plastic blade, to both feet turns conventional swimming to the turbo-charged fin swimming. A snorkel, braced over the athlete’s forehead and nose, is used in addition to the mono fin for surface racing.