Houghton Mifflin Harcourt, 2014, 272 pages
Deep is a voyage from the ocean's surface to its darkest trenches, the most mysterious places on Earth. Fascinated by the sport of freediving - in which competitors descend to great depths on a single breath - James Nestor embeds with a gang of oceangoing extreme athletes and renegade researchers. He finds whales that communicate with other whales hundreds of miles away, sharks that swim in unerringly straight lines through pitch-black waters, and other strange phenomena. Most illuminating of all, he learns that these abilities are reflected in our own remarkable and often hidden potential - including echolocation, directional sense, and the profound bodily changes humans undergo when underwater. Along the way Nestor unlocks his own freediving skills as he communes with the pioneers who are expanding our definition of what is possible in the natural world - and in ourselves.
Freediving is about half very interesting book and half rather dull journalistic travelogue. The interesting parts are when the author introduces us to freediving — the sport of diving as deep as possible without gear, just the air in your lungs. It's one of those "extreme" sports that becomes fashionable with certain types of thrill-seekers, but freediving attracts people of all ages and body types. While the book's blurb, implying that we're a naturally aquatic species if we just remembered, is a little misleading, it turns out that our bodies are better adapted to swimming and diving than we may think. I always thought you needed scuba gear to go more than a couple dozen feet down, but it turns out that you can actually adapt your body to dive very deep indeed, and come up again, on just one lungful of air. (The current world record is 831 feet!)
But make no mistake, it's a dangerous sport. Freedivers regularly come up gushing blood from their nose and ears, and there is an ever-present threat of blacking out, or suffering from the bends. When freedivers drown, they usually drown coming back up, while only a few feet from the surface, not while they're down deep. Much of Deep is padded with a history of mankind's attempts at deep sea exploration, diving experimentation, and all the interesting ways people have died underwater.
There is also some stuff about the oceans and marine biology. Sharks are rarely a hazard for freedivers, but they have been hazards for divers, surfers, kayakers, and anyone else who goes into the water from time to time, and Nestor writes about them a little bit. He repeats the usual factoids about how sharks rarely attack humans, and when they do it's often around places like underwater garbage piles where people have been dumping their trash. Still, they are not creatures to mess with.
Neither are whales. Nestor also does some freediving with them. It turns out this is rarely done, and for good reason as it can be dangerous, even though there are no recorded instances of whales eating people. Whales are really, really big and when they "play" they can kill you. I also learned that an adult sperm whale's sonar clicks can stun a grown man. Nestor does some theorizing about whale communication and talks briefly about the history of whaling, but this read like more padding.
If you are interested in the sport of freediving but have no intention of leaving dry land to do it, this was an interesting book, but it really could have been just a long magazine article.
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