The German submarine U-505 endured one of the most bizarre and brutal careers of any vessel to survive the Second World War. Commissioned in Hamburg in August 1941 as a long-range Type IXC U-boat, it sank four Allied ships in a single month off West Africa, then torpedoed a Colombian sailing vessel owned by a diplomat, handing Colombia the justification it needed to declare war on Germany. From there its luck collapsed: a British bomber dropped a 250-pound bomb directly on its deck near Trinidad, French Resistance dock workers in Lorient quietly sabotaged six consecutive patrols, and in October 1943, under a depth-charge attack near the Azores, Commander Peter Zschech took his own life in the control room while his first watch officer brought the boat home.

Drawing on declassified US Navy intelligence reports, captured German naval logs, an ...