We're born of the ocean. ...At the fifth week of a fetus's development, its heart has two chambers, a characteristic shared by fish. - James Nestor

An infant will reflexively breaststroke when placed when placed underwater and comfortably hold his breath... longer than many adults.

If you were to take [a billiard ball]... and... imagine just pushing it inside your head, that's about the volume of your nose and all your sinus cavities. ...[T]hey even stretch out above your eyes... [T]hey call it the because it looks exactly like a seashell.

At sixty feet... The heart beats at half its normal rate. Blood starts rushing... toward the more critical... core. ...The senses numb, the synapses slow. The brain enters a heavily meditative state.