They're able to see better with sounds than we are able to see with our eyes. - James Nestor

Scientists call it the mammalian dive reflex or...the Master Switch of Life, and they've been researching it for... fifty years. ...[C]oined by Per Scholander ...it refers to variety of physiological reflexes in the brain, lungs, heart [etc.] that are triggered the second we put our face in the water. The deeper... the more pronounced... Ancient cultures... employed it... to harvest sponges, pearls, coral and food hudreds of feet below the surface of the ocean...

[B]est of all, divers will tell you, "It's open to everyone."

So you can breath less and get more by breathing through the nose.