A fascinating ten-years-later sequel to The Silent World. In the Red Sea, on a reef too deep for the 1951 techniques of the inventor of the Aqua Lung, Cousteau evolved the methods and the equipment for deeper exploration. A grounded lobster diver's confidence about ""old jars"" off France led to the revelation of a ship that had been wrecked some 2000 years before Christ and a five year salvage venture that cost the expedition a life. Always, the sense of pioneer exploration with its tension and mystery is present. Cousteau's battle to save undersea exploration from the additional hazards present in the dumping of atomic wastes is fully reported.