Recently, as the exploration of the oceans and the sea-bed has become less commercial and more scientific in purpose, books about diving have won a wide readership. All of us are entranced by the new knowledge brought up from this secret world.

No man has done so much to open the door to this world and to reveal its mysteries as Capt. Jacques-Yves Cousteau. Certainly no other man is so uniquely fitted for the self-imposed task. A seaman, qualified to command any vessel in the French fleet, superb navigator, highly skilled diver, gunner, aerial observer, inventor of the Aqua-Lung, he is also a scientist, with a gift for explaining scientific problems.

Captain Cousteau's previous book, "The Silent World," was translated into 22 languages and sold more than three million copies in English alone. It will be surprising if "The Living Sea"—which he has written with freelance writer James...