Finswimming is an underwater sport consisting of four techniques involving swimming .. Maximum output with some simple thoughts...
After the start and after each turn, at any time prior to the first breast
stroke kick, a single butterfly dolphin kick is permitted, following which,
all movements of the legs shall be simultaneous and in the same horizontal
plane without alternating movement.
The feet must be turned outwards during the propulsive part of the kick.
Scissors, alternating movements, or downward butterfly dolphin kicks are
not permitted except as provided herein. Breaking the surface of the water
with the feet is allowed unless followed by a downward butterfly dolphin