From the back cover:

When re-armament came after World War I, the German Navy was forced to build anew, so the Reichsmarine and its successor, the Kriegsmarine, found itself in possession of some of the most modern, powerful and technically advanced vessels in the world. Germany was very selective in picking her sailors and the quality of manpower skill levels was thus very high. This book charts the recruitment, training, service conditions and combat experiences of a typical World War II German sailor, focusing on the main branches of the Navy, as well as the last ditch combat units thrown into action as infantry in the final days of the war.