Deep: Freediving, Renegade Science, and What the Ocean Tells Us About Ourselves

"This book also has a million Post-it notes on it. Deep explores the ocean from its surface to its depths via the extreme sport of freediving, where divers descend as deep into the ocean as they can on a single breath. Nestor frames a freediver’s descent into the ocean through a closeup of the human body and what happens to it, in terms of the pressure on the body and the oxygen supply, and uncovers some stunning revelations. It’s an intimate, human look at diving. Nestor also looks beyond freediving into many other areas, including what can be found on the seafloor and why that matters to humanity. Nestor has recently published a book called Breath , which is a detailed portrait about what happens when we breathe. You can see how writing the freediving book may have inspired his next book. Earlier in the last century, there was this aquatic ape theory that modern humans descended from an ape that was more adapted to the ocean. It was suggested that this is why we’re mostly hairless like whales, why we have this diving reflex to hold our breath from a young age. Now we know that this theory is not correct. We do know that life started in water, that the first organisms appeared in the deep sea, likely at hydrothermal vents, where the first chemical sparks of life caught fire. That life evolved first in the ocean and then eventually crawled out of the seas and then long after that humans appeared. Still, we have a lot of deep ties to the water. Our bodies are mostly water. The womb contains fluid that’s very similar to seawater, and a lot of our features in the early stages of development appear somewhat fish-like. Every other breath we take depends on the ocean—it’s oxygen produced by the ocean. James Nestor’s book looks into all the ways in which we’re linked to the ocean."