HMS SALMON (Cdr E O Bickford, DSO) was the first Royal Navy submarine to sink a U-Boat in WW2, U-36 (Wilhelm Frolich), in the North Sea southwest of Stavanger on 4 December 1939. On 13 December 1939, he also sighted and attacked the German Cruisers LEIPZIG and NURNBERG and hit both ships with the same salvo of torpedoes, one hit on each Ship. For these exploits, the Commanding Officer was awarded the Distinguished Service Order (DSO).
In 1940, HMS SALMON sailed from Rosyth on 4 July for a patrol area off southwest Norway. She was sent a signal on 12 July 1940 with instructions to return to base. HMS SALMON was declared overdue on 16 July 1940 and was subsequently assumed to have been lost with All Hands. Later it was realised that an earlier signal to SALMON had routed her across a minefield which was, at the time of her passage, unknown to the Admiralty.