Breaking German, Italian and Japanese naval codes was vital to the war effort
The intelligence produced by deciphering Naval Enigma was passed to the Admiralty by Naval Section. In the early days, they struggled to get the naval commanders to take it seriously, but a series of spectacular successes turned things around for the Codebreakers.The second half of 1941 saw Hut 8, led by Alan Turing, make the breakthrough on the Dolphin Enigma key used by the U-Boats attacking the trans-Atlantic convoys. From then on, throughout the Battle of the Atlantic, they helped the Admiralty to track the U-Boat wolf packs, considerably reducing the German Navy’s ability to sink the merchant navy ships bringing vital supplies to Britain from America.
In the Mediterranean, the Battle of Matapan in March 1941 was a direct result of Bletchley Park’s break into the Italian Naval Enigma system, which led to a Royal Navy victory that restricted the Italian Navy’s operations for the rest of the war. Also in the Far East, reading Japanese codes led to routine sinking of enemy ships.