I think that one of the best ways to learn proper butterfly
is to do the stroke with flippers on. Timing, aside from
upper body strength, is the most important aspect of this stroke.
The flippers will exaggerate the kicking motion and will
allow the swimmer to feel the motion in his/her legs. Also,
the added thrust lets the beginning swimmer get the upper body
out of the water more, letting the recovery stroke take place
in the air instead of the water. If you ever watch a beginner
learn fly, after about half a lap, the recovery stroke is as
far under the water as the power stroke! This leads to an
exponential(sp?) decrease in endurance.
Just one person's opinion.
Northern Telecom Inc.