German U-boats had almost brought Britain to its knees in World War 1. Twenty years later the blockade was worse. The German U-boat arm came within a whisker of cutting the lifeline that stretched from America to Europe across the Atlantic Ocean: indeed, had it not been for Ultra, and the decrypting of so much Kriegsmarine radio traffic, the final story could have been very different. What was it like to be a member of a U-boat crew? Wolf Pack at War provides the truth behind the image portrayed so convincingly in the film Das Boot. After the 'happy time' of the early war years, when the U-boats struck seemingly at will and to great effect, the later war years were much grimmer for the Krlegsmarine. Their shore bases bombed incessantly by the Allies, the skies above the Atlantic patrolled by deadly long-range submarine busters like the short Sunderland and their movements tracked by Ultra decrypts and radar, the U-boat crews went to sea knowing that their life expectancy was short and their fate likely to be a watery grave. This is their story, illustrated by a remarkable collection of rare photographs and illustrations, many in colour. This book gives an essential account of one of the most important theatres of wartime operation. It will appeal to those interested specifically in the history of naval warfare and also those with a broader interest in the strategy and tactics of the war.