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 Dugan—does not surpass that record. Whether Captain Cousteau is describing the recovery of artifacts from a Greek galley sunk more than two centuries before Christ, or his battle to prevent the dumping of radioactive waste into the Mediterranean, he is unfailingly interesting.

His descriptions gracefully combine literary style and scientific nomenclature….

The mobile base for the explorations reported in this book was the oceanographic ship Calypso, well-equipped with depth-probing devices and a professional diving team. The log unfolded in these pages records episodes ranging over the Atlantic, the Mediterranean and the Red Sea. Included are trips to discover ocean-bed oil deposits and to help lay electrical cables in the Gulf of Lion off the south coast of France. There is a strange journey to "hunt water underwater"—that is, a fresh water supply for the sea town of Cassis east of Marseille.

There is something along the way for all tastes. Oddities abound for curiosity-seekers. Cousteau reports seeing a number of creatures never reported before, including "a fish twenty inches long and shaped exactly like a draftsman's triangle. It was the shade and thinness of aluminum foil with a ridiculous little tail." He records also, on his underwater writing pad, a squid that squirts white ink; a shark observed at 13,000 feet, where no shark has any right to live; and a wall of breakers in the Red Sea that resolved itself into thousands of dolphins prancing 15 feet into the air to breathe.

Perhaps most astonishing is an undersea avalanche set off by Cousteau and his partner Houot with their bathyscaph off Toulon. A wall gave way on the edge of a huge trench, muddying the sea for miles and almost burying the bathyscaph. Later, Cousteau remarked to a scientist he knew: "Remember that canyon off Toulon that you charted so carefully? You'll have to do it again. Houot and I have just wrecked it."

For the scientifically minded interested in the progress and possibilities of submarine exploration, there are chapters on the revolutionary "soucoupe plongeante" or "Diving Saucer". This is an underwater vehicle designed to allow its occupants to examine in safety and comfort the continental shelf which comprises 8 per cent of the oceanic surface of the globe—an area equal to that of Asia. (p. 1)

The DS-2, as Cousteau called his saucer, is no Jules Verne pipedream. Apart from some initial trouble with batteries, it has been completely successful in more than 60 scientific missions and the tape-recorded underwater logs have yielded a mass of information on life in the sea. The other devices used include the Deepsea Camera Sled, which travels miles below the surface photographing phenomena never before seen by man; submarine self-propelled "scooters" for use with the Aqua-Lung and nylon anchor-cables six miles long to which a vessel can ride.

The historically minded may prefer to read about the salvage of tools, fittings, pottery and 7,000 wine amphorae—earthware containers that were "the jerry cans of antiquity"—from the sunken wreck off Marseille. There is something strangely intriguing to Cousteau in the notion of sipping wine that was bottled and shipped commercially more than two thousand years ago—and finding that it has the resinous flavor of Greek wines of today.

No less intriguing is the notion of producing a Homo Aquaticus, a new man free to roam below the surface as his cousins do above. In an experiment which is the climax of the book, two men, under Captain Cousteau's supervision, lived and worked under water continuously for a week, in a chamber with a hatch open always to the sea and kept down by internal air pressure. Through this liquid door they passed in and out: inside they lived and read and slept and watched television. The experiment, which produced some strange psychological effects—the men became detached about worldly concerns, such as modesty, for example—may be of great importance. It is characteristic of Captain Cousteau that he does not forget that Sir Robert Davis, the great British expert on diving, now aged 93 and still active, devised just such an underwater dwelling more than 30 years ago. (pp. 1, 36)

[The] author does a service by pointing out that for the Aqua-Lung enthusiast, the sea is still a dangerous place—not only because of sharks. Though Cousteau exceeds it himself, 140 feet is still the normal limit of safety for even the skilled skin-diver. Below that lies depth-drunkenness, "the zone of rapture," where a man loses all sense of risk.

The amateur would be wise to limit himself, not to 140 feet, but to half that depth at the outside…. Most of us must, then, be content to see all these submarine marvels vicariously. Thanks to Captain Cousteau, we can do so, with immense pleasure, in this entrancing book. (p. 36)