During the Second World War, long-range German submarines, commonly referred to by their German name Unterseeboot, or U-boat, ranged the American coastline and placed a stranglehold on the flow of vital war supplies. The shipping lanes off Cape Hatteras, North Carolina were prime hunting ground for these feared sea hunters. As the war raged on, however, Allied destroyers using the newly invented sonar and radar began to hunt down and destroy the U-boats as they moved in to attack. There are six U-boats resting on the seabed near Cape Hatteras, known to mariners as "the Graveyard of the...