This is the complete wartime translation by the U.S. Navy of the 1943 edition of the official handbook given to all U-boat commanders. The original handbook was compiled from combat reports and was regularly updated throughout the war. The handbook was an invaluable reference for every operational U-boat commander. Simply written and highly accessible for a wider audience, the U-boat handbook attempted to anticipate every possible situation and to advise on suitable tactics. This superb war-time primary source is enhanced by a rare series of photographs taken on an actual combat patrol and published during the time of the Third Reich in the book "U-Boot Auf Feindfahrt." Together the handbook and these rare photographs provide a fascinating glimpse into the world of the U-boats from a first hand perspective, and is essential reading for anyone interested in World War II from primary sources.