A TI video, https://www.youtube.com/watch?v=voGWW36dQwE
(5:00), suggests that fins may be useful in learning the basic butterfly body rhythm. The fins used by the person in the film seem somewhat longer than the standard swim training fins. I am thinking of buying some fins. (With just feet, I don't seem to make a lot of progress in the water.) Could anybody provide any advice on what sort of fins would be best for learning butterfly?