Battle of the Atlantic

Location: Atlantic Ocean

Date: September 1939 – May - 1943

Commanders and Forces: German: 1000 U-Boats (Rear Admiral Karl Donitz) British: 9 battleships, 4 aircraft carriers, 35 cruisers, 95 destroyers and 25 submarines. (Admiral Sir Charles Forbes)

Casualties: German: 19,000 killed Allied: 85,000 killed

Key Actions: After taking heavy losses in the first part of the war, from early 1943 onward British strategy and equipment improved. More aggressive anti-submarine tactics, better depth charges, and the fitting of long-range aircraft with improved radar ensured that U-Boat losses rose. A total of 45 German submarines were destroyed in April and May 1943. Germans, seeing that such losses could not be tolerated, called off the battle on May 23, 1943. Although the German U-boat threat did not completely disappear, after this time it was greatly diminished.

Key Effects: The U-boat threat was probably the single most serious threat to Britain during WW11. If the Germans had been able to deploy more U-boats in 1940 and 1941, then the course of WW11 would have been very different, with Britain perhaps starved into submission.