Captain Joe Baker-Cresswell, the Royal Navy skipper whose shrewd move during a sea

battle played a major part in Germany losing the Second World War, has died aged 96. He could have ordered the destruction of a German U-boat his ship HMS Bulldog crippled in the North Atlantic on May 9, 1941, but instead he had it searched.

As a result, an Enigma encoding machine was discovered and this enabled the Allies to decipher enemy naval plans - which King George VI later described as the most significant event of the war at sea. The King decorated Capt Baker-Cresswell with the Distinguished Service Order.

In a tribute to him today, Viscount Ridley said: ''He was a magnificent sailor and a real war hero. His contribution to the victory in 1945 was immense.

The action began with U-110 torpedoing two ships in an Allied convoy south of Greenland. This led to a counter-attack from the Bulldog which forced the U-boat to the surface with depth charges.

Allied warships were about to go in for the kill when Capt Baker-Cresswell remembered a lecture about how ciphers were captured during a First World War battle. So he ordered that it should be boarded instead.

Capt Baker-Cresswell was born into a Northumberland land-owning family in 1901. Educated at Greshams, he was commissioned in the Royal Navy in 1918. While based at Auckland, New Zealand, in 1926 he met and married his wife, Rona, who survives him. They had three children: Charles, Pam, and Rosemary.

He died at his home near Bamburgh, in Northumberland, on Tuesday.