The infamous U boats deployed by Germany in the two World Wars have spawned several works of fiction and non-fiction. These deadly vessels were not just efficient and lethal killing machines, but they were also used very effectively in economic blockades. They were positioned primarily to obstruct the conveyance of fuel, food and other essential supplies which the enemy needed to sustain the war effort. In the Diary of a U Boat Commander, the author, Stephen King-Hall draws upon his vast per ...