Sunken treasure and skin-diving are a sure-fire combination for reader interest. To find it in non-fiction, well written by an experienced author and illustrated by an expert underwater photographer as well, makes it no risk at all to predict the book's success in sales and circulation. Off the southwest coast of eylon in 1961, while putting together a movie fantasy featuring two young boys, photographer Mike Wilson and the youngsters found a fabulous wreck on the ocean floor -- a solid wall of coins from a 260 years old ship that had left an Indian int with new money and had sunk to a depth impossible for men to reach in the 700's. The immediate problem after discovery was security -- the secret had to be kept from treasure hunters. Peter Throckmorton (see his recent book p. 559 J-179) was called in as underwater archaeological expert and Clarke with Wilson began to arrange the finances for the recovery of the treasure. Beset by weather, family problems, technical difficulties and money troubles, the work was begun. It is still not finished, promising another good book.