Early in the summer of his sixteenth year, Chuck Crawfod blurts out his dilemma to an older, wiser friend. ""I don't know what anything's about. Nothing makes sense. Life and things like that. Being born. And all that."" ""It's tough sometimes,"" his stoical friend agrees. Trying to teach Chuck the true values of life, Tom begins training him to scubs dive off the California Coast. In the watery depths, he implies, even a lonely introvert like Chuck can learn to recognize danger and meet it in spite of his fears -- a lesson with obvious implications. Once Chuck is a competent diver, the plot revolves around his attempt with Tom to salvage an airplane wreckage buried twenty fathoms under the ocean. Here author O'Connor really redeems himself: his descriptions of the water's releatiess pressure, of the diver's hazy blue-green world, are superb. Back ashore things are a bit too pat again: the project is successful, Chuck has scored a personal and financial triumph, and a romance with Tom's niece is well underway. Except when its characters come up for air, Treasure is an atmosphere-laden adventure with lots of incidental information about skin diving.