Hitler confessed that although he was a hero on land, he was a coward at sea, and this son of landlocked Austria never took the same interest in the Kriegsmarine as in the other two armed services. Even so, the Navy were allotted funds for the building of battleships like the Bismarck, Tirpitz and Prinz Eugen and the smaller Scharnhorst and Gneisenau. Even more resources were channeled into building up the Navy’s U-boat arm under Admiral Karl Doenitz. When the war began, the U-boats acquired bases on the French Atlantic coasts from which to harry Britain’s trans-Atlantic supply lines in their wolf packs. Only the adoption of the convoy system, the breaking of the Navy’s Enigma codes, and the development of sophisticated anti-submarine devices prevented the strangling of Britain economically. Germany’s surface fleet suffered crippling blows with the loss of the Bismarck, and the bottling up of other capital ships, and by the war’s end, Germany’s vaunted navy had been effectively destroyed.