An official history of that phase of World War II amphibious operations, better known as the work of UDT or Underwater Demolition Teams, extensively covers the activities of this section of the Navy from its origin on through the many maneuvers, small and large, which aided the Allies in the South Pacific, the Atlantic and in the Korean campaign. While introductory chapters deal with the concept of UDT, the changes in its training programs and its purposes- to find dangerous inshore obstructions and facilitate the landing of troops against immediate opposition- these are followed with play by play descriptions of various invasions and invasion campaigns. There was Saipan and the first major test of the newly organized UDT; Guam and the decisive operations of two men, Crist and Carberry; the Halsey-MacArthur tactics of 1944 and the far reaching results they brought, climaxing on Okinawa. Except for those with the special interest the book will make dry reading, for it is long, meticulously detailed and written without facility of expression that could have made a more notable book of UDT's basically exciting story. Nevertheless the remarkable accomplishments and deeds this small body of highly trained men performed is recorded here to their much deserved credit.