U-Boat

The U-boat, from the German Unterseeboot, was the submarine of the Imperial and later Nazi German navies, central to both Battles of the Atlantic. In the First World War unrestricted U-boat warfare from 1917 nearly severed Britain’s supply lines and helped bring the United States into the war. In the Second, Donitz’s wolfpacks sank millions of tons of Allied shipping before escort carriers, aircraft, radar, and broken Enigma traffic defeated them by mid-1943. Preserved boats and wrecks are studied and dived today.