This aimless underwater excursion explores the specialized world of the coral reef. From a gushy beginning--the reef ""looks like a fairyland. . . a place of towers and tunnels, caves and castles""--it settles clown soon enough to a sketchy description of the reef and its formation, listing flora and fauna, and relating the shape, markings, and behavior of fish to their habitat. The text is sometimes not matched with the illustrations--told ""here comes a four-foot grouper with a huge mouth,"" we're disappointed to look up at a photo of a snout-nosed trumpetfish--and readers familiar with Jacques Cousteau may find the sickly-pale technicolor photographs a bit tame. Cursory.