Perhaps we should start now with high school courses devoted simply to The Sea, for the time is approaching when oceanography may well outstrip Space as a consuming interest of science. Among recent studies the best is Cousteau's The Living Sea (1963), which limits itself to underwater experiments but is written with such coruscating brilliance that the imagination dances. Gardner Soule's The Ocean Adventure (p. 721) has considerably more breadth and detail than Deep Challenge, but both seem pedestrian assignments when compared with Cousteau. Between Ocean and Deep, Ocean is the better $5.95. The present book's two high spots are about tsunamis (Japanese for ""great waves"") and a futuramic fantasy about aqua-hotels and resorts on the seabottom before 2000. The rest is a Reader's Digest level survey of the global sea, the trenches, the tides, the chemistry of the water, abundance of life, mineral wealth and so on, all in a plankton prose occasionally enlivened with bumptious verse. Dr. Stewart personally has engaged in some pioneering expeditions which were certainly more interesting than this routine chore. No challenge.