The author, Susan Casey, is fascinated with the deep sea and there's a whole chapter covering William Beebe, whose adventures in his Bathysphere fascinated me when I was in elementary school. I used to draw elaborately layered views of the ocean depths, teeming with all the strange critters he reported.
She also talks about diving off Hawaii in the Pisces-class subs operated by the Hawaii Underwater Research Laboratory and the book climaxes with her accompanying Vescovo* for part of his Five Deeps Expedition.
Although a journalist, Casey writes with a novelist's eye for people and action, and the book steps right along with a very "you are there" vibe. Definitely recommend.
*Vescovo is the only dude to have been to the top of Everest, the bottom of the Marianas Trench, and outer space. (Also the North and South Poles.)
