Deep: Freediving, Renegade Science, and What the Ocean Tells Us About Ourselves

by James Nestor

Once his volunteers were underwater, the blood in their bodies began flooding away from their limbs and toward their vital organs.

This shunting is called peripheral vasoconstriction, and it explains how Bucher could dive to below one hundred feet without suffering the lung-crushing effects that Boyle’s law had predicted.

Scholander found that a person need submerge only his face in water to activate these life-lengthening (and lifesaving) reflexes.