Drownproofing

[4] Once they had mastered the Drownproofing technique, students learned to stay afloat with their wrists and ankles bound, swim 50 yards (46 m) underwater, and retrieve diving rings from the bottom of the pool using their teeth.

Reagh "Doc" Wetmore, swimming coach at Boston University, shared Fred Lanoue's enthusiasm for Drownproofing and continued to teach the technique until his retirement at the end of 2005.

Using the arms or legs to exert a downward pressure, the subject raises himself sufficiently so that the mouth is above the surface and a breath is taken, before dropping back into the relaxed float.

The main criticism of Drownproofing is that, with the body almost totally immersed, heat loss will be greater than with vigorous swimming or treading water, with the consequent earlier onset of hypothermia.

[9][citation needed] But other sources suggest that heat loss is increased by vigorous action, because it displaces relatively warmer water that is trapped by the subject's clothing.

It can be adapted and used as part of the drownproofing technique but is far more challenging due to the physical exertion required to hold your body in this shape, and the near impossibility of keeping your legs pressed to your torso while your hands are bound behind your back.[why?]