Alternative title: Smart People Who Do Astonishingly Scary Things
First off, the thing that grabs you is the anecdotes about the early days of freediving and scuba diving. There are funny ones and grim ones and gross ones. But James Nestor, the author, doesn't just relate fish tales (sorry) but makes it meaningful You can look at the book from several angles, and freediving is just one facet of it.
First is the sport itself and the many ways humans have tried to get beneath the sea, how far they've gotten, and what the actual technique is for record-setting dives. On his initial experience of seeing freedivers, the first thing he does is call his mother. She tells him to do better research rather than report such nonsense. That little bit just set the tone for me: inspired, amusing, but pragmatic. His voice as an author is pleasant, never lecturing too much or flooding raw data but explaining the context. Sure, if there's a gross anecdote to tell, it's in here, and these keep you on your toes (sort of like car wrecks at races).
Second is the "why" factor, what secrets does the deep sea hold for scientists and research and ultimately humans? How much do we really know about its unplumbed depths? Not much, it appears. He explains just what is being done now and what could be discovered. The scale of the ocean is beyond our understanding as we take for granted just how much water covers the earth without considering what is within it in terms of species and formations.
Part of why I sort of loved this was that I read it at the community pool while my son had swim lessons. Something about being by the water made it real, and of course, I had to go swim for pennies in the 12 foot area to see how long I could hold my breath. Not long. Certainly not hundreds of feet like those in the book. And obviously, the local pool has no sharks.
I think the curiosity of humans and their quest for the unknown is a fascinating subject. Could it be we know more about the moon than under the sea just a few miles out? Seeing all these different researchers pursue their studies, even when the effects or results are only likely to be relevant years from now, maybe long after their natural lifespan, is intriguing. It's almost a higher calling, this pursuit of knowledge for the gain of future generations. Perhaps the names in this book will become as famous as Curie or Pasteur or Cousteau.
Some nonfiction works are either too light or way too deep, with the writer either trying to be glib and dumb down the subject, or show how many references they can cite and leave you lost. This balances both well, not an easy thing to do and not always easy to find as a reader. If you are a fan of Erik Larson (The Devil in the White City) or Bill Streever (Cold: Adventures int he World's Frozen Places), you will probably enjoy this.