As a point of reference, German U-boats terrorized Atlantic shipping convoys during World War II.  The book, U-boat War, is the fascinating story of Hitler's U-boat fleet operations from 1939 to 1945 and covers their history, as well as, the different models utilized during this period.  In addition to an informative text, this book includes the following: 1) Extensive collection of vintage black ad white photographs; 2) Eight pages of color illustrations and 3) Full appendices.  This book is 64 pages.  The author is Timothy J. Kutta.  Edition published in 1998.