[Y]our body wants to be in balance... the right amount of CO₂ and oxygen for optimum delivery, and that's what the nose helps you to do. - James Nestor

He... had dolphin English language immersion workshops... where... an intern [would] grant dolphins sexual favors if they learned English words, and this... worked.

[A]fter around 30 feet... the water stops buoying you... and starts dragging you down to the sea floor. ...[T]he deeper ...the more your body changes. ...Your organs allow for the free flow of fluids so they don't collapse. Your brain waves slow down. Your heart rate will slow to about 1/3 its resting rate.

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.