Soggy:Why do you need to be in a lotus position to learn about the efefcts of buoyancy and breathing? Why not assume a useful position, like horizontal?
It forces the diver into a position in which it is virtually impossible to use subtle fin movements, hand sculling, or other movements to maintain position in the water. You really only can do this if you trim is correct, you are totally neutral, and totally relaxed. Is it a useful skill, like mask clearing? The answer is obviously no. Is it a useful exercise? Yes. It helps students understand the importance of trim, neutral buoyancy, relaxation, and breathing control.