Announcing a new Landmark book: The fashions in war heroes change and, at the moment, the Underwater Demolition Teams are in the ascendant. Better known as ""Frogmen,"" their stories combine the irresistible factors of skindiving techniques with those of explosive warfare. It's a winning combination, and this book starts with the feats of Italian, British and Scandinavian Frogmen prior to our entry in W. II. The U.S. was late in developing UDT teams, but as the war in the Pacific progressed, the necessity for advance, underwater reconnaissance before troops could be landed on Japanese-held islands, became tragically apparent. Once started, the U.S. caught up with and bypassed the pioneers in this method of warfare. Mr. lassingame has made the book an anecdotal record in chronological sequence. Dire necessity and extreme danger were the mothers of most of the techniques adopted, and many were discovered and suggested by the ranks rather than the officers.