1st.ed., 1989. 190 pp., profusely illustrated with photographs, maps, charts, diagrams, tables, etc. D.j., 25 x 25cm. Nr.FINE. During the course of two World Wars, German submarines sank 8,209 merchant vessels grossing more than 27 million tons. This book ' illustrated with over 150 photographs, diagrams, maps etc., ' sets out to compare the two U-boat offensives. The author has researched among a great deal of hitherto unpublished material in both British and German archives in order to chronicle the strategic and tactical evolution of the offensives. He also describes Allied anti-submarine measures evolved to combat and decisively defeat the threat to transatlantic shipping. The Appendices provide further tables, charts and diagrams and provide statistics more accurate than any previously published ' including cause of loss details for every U-boat sunk in each war.