Journalist James Nestor looks into the sport of freediving, and finds a world of beauty under the ocean.
The genesis of James Nestor’s “Deep” was a magazine assignment to cover the 2011 Individual Depth World Championships. That’s a competition in freediving, a sport in which participants hold their breath for several minutes and plunge hundreds of feet into the ocean’s depths.
As they head deeper into the waters, the pressure on their bodies increases exponentially. At 60 feet, “the heart beats at half its normal rate,” Nestor writes. At 300 feet, “the organs collapse. The heart beats at a quarter of its normal rate, slower than the rate of a person in a coma.”
As they continue to descend, the entire chest cavity shrinks to less than half its above-water size, all a kind of safety mechanism to protect the diver.
It is this primeval response to the depths that fascinated Nestor. He uses the term Master Switch of Life — it’s also called mammalian diving reflex — which “refers to a variety of physiological reflexes in the brains, lungs and heart, among other organs, that are triggered the second we put our faces in the water.”
Nestor suggests it comes from some vestigial remnant of our distant waterlogged past. We have other extrasensory abilities, he claims, “latent and mostly unused in humans, but they have not disappeared.”
One is echolocation, a kind of radar used by sharks, dolphins and whales in deep water where there is no light, and by bats in flight to make their way around. Another is magnetoreception, the sense animals use to migrate. But since these abilities, fascinating as they may be, are not limited to sea creatures, it dilutes Nestor’s goal “to write about the human connection to the ocean.”
Clearly, we are connected. Three-quarters of the planet is covered by water, and about half of the known creatures in the world live in water. Much of the world’s oxygen is generated by ocean-borne algae.
Nestor is at his best when he’s with folks who are involved in research and diving. He spends time with aquanauts who volunteer to have their bodies super-compressed so they can dive for as long as they want without worrying about compression sickness.
He meets a free diver whose goal is “to find the human body’s absolute limits, break it and thus extend human potential.”
The ocean will soon be front and center in pop culture. James Cameron’s new film, “Deepsea Challenge 3D,” gets widespread release Aug. 8. The director who popularized the expression “I’m king of the world” goes down to the bottom of it in a risky mission on a submersible and films new forms of life.
“Deep” will — you should pardon the expression — whet the public’s appetite for it.
Curt Schleier is a freelance writer and critic in New Jersey.