For readers with more than a slight interest in oceanography this is a reasonably good introduction to a complex field. The brief articles by 29 authors on many phases of this relatively new science (although oceans were studied by the ancients, real work on this area which covers about 70% of the earth's surface did not begin until the 1600's) include glimpses of such diverse concerns as ocean sediment as a key to the past, deep ocean circulation, the multiple use of the coastal environment, and upwelling and monsoons, to name a few. Unfortunately, only four of the 28 chapters have references (and most of those are to rather technical journals), and there is no bibliography or list of suggested books to which the reader might turn for more information. The perhaps overly brief introduction by Jacques Cousteau, in his very personal style, hints at the excitement of underwater research and while the rest of the more technical articles are crammed with facts, most of them are not likely to inspire one to join a deep-sea expedition. To its credit, however, the book, while dealing with a scientific subject, is usually readable on the layman level and, although the concepts are of necessity highly condensed, they do include appropriate background information. The title sums up the wonder of the oceans: they are the last frontier left on earth and Vetter has brought together enough information on them to whet our curiosity.