Battle of the Atlantic

Battle of the Atlantic

It is commonly claimed that breaking of German Naval Enigma shortened the war by a year, but given its effects on the Second Battle of the Atlantic alone, that might be an underestimate.

An exhibit in 2003 on "Secret War" at the Imperial War Museum, in London, quoted British Prime Minister Winston Churchill telling King George VI, "It was thanks to Ultra that we won the war." Churchill's greatest fear, even after Hitler had suspended Operation Sealion and invaded the Soviet Union, was that the German submarine wolf packs would succeed in strangling sea-locked Britain. He would later write, in Their Finest Hour (1949), "The only thing that ever really frightened me during the war was the U-boat peril."[23] A major factor that averted Britain's defeat in the Battle of the Atlantic was her regained mastery of Naval Enigma decryption.

There were, however, also other technologies, equipment and tactics that moved the Battle of the Atlantic in the Allies' favor. As the air gap over the North Atlantic closed and convoys received escort carrier protection, anti-submarine aircraft became efficient hunter-killers with the use of centimetric radar and airborne depth charges. Improvements to Huff-Duff (radio-triangulation used as part of ELINT) meant that a U-boat could be located even if its messages could not be read. (Simply avoiding a known submarine often sufficed.) Improvements to ASDIC (SONAR), coupled with Hedgehog, enhanced the likelihood of sinking a U-boat.