This is the first comprehensive English-language study of S-Boat, or Schnellboat, actions during World War II in all the theatres where they were deployed. The German 40-knot motor torpedo boat (German: S-Boat, English: E-Boat) was a controversial subject in the pre war period of German naval rearmament. As late as 1938, the Fleet Commander recommended that S-Boat building be terminated on the grounds that the craft was merely a 'weapon of opportunity' without a defined role. This outlook soon changed after the first dramatic wartime successes. Soon the S-Boat was required on all fronts, and the areas of operations eventually extended from the North Cape to the Mediterranean, and from the English Channel to the Baltic and the Black Sea. The operational deployment of the S-Boat in all these theatres is given comprehensive treatment and not purely from the isolated viewpoint of S-Boat warfare, but as an integral part of the overall military objectives of the time. The author analyses the effectiveness of the S-Boat, its successes and failures , and much of his study is based on war diary entries and previously unseen original sources. Illustrated with an extensive collection of new photographs and specially commissioned maps, the book is an outstanding account of this German naval arm that survived to be the last class of surface warship carrying the offensive to the enemy. AUTHOR: Hans Frank served in the Federal German Navy from 1961 until 1999 where he rose to be Commanding Officer of the S-Boat Flotilla. He founded the S-Boat Flotilla Veterans' Association, whose archive contains a store of personal histories submitted by former S-Boat men. Along with numerous publications on defence and maritime strategy, he is the author of several studies respecting S-Boat operations. b/w photos throughout