On the evening of April 9, 1940, H.M.S. Truant, a submarine of 1,090 tons, completed early in the war, torpedoed the German cruiser Karlsruhe off Kristiansand while that ship was engaged in covering the enemy invasion of Norway. Though hunted by destroyers for 4½ hours, she escaped with slight damage from depth charges. Not long afterwards, while on passage to Gibraltar, she intercepted and recaptured the Norwegian motor ship Tropic Sea, which the Germans had seized.
In the Mediterranean the Truant was active in operations against Italian convoys proceeding to Libya. In December 1940 she destroyed two supply ships and a tanker; and in March 1941 she entered the harbour of Buerat, in the Gulf of Sirte, to attack another tanker. While engaged in sinking an enemy ship in the Adriatic she was obliged to dive in 20 feet of water, with the result that her bows became embedded in the mud.
Later the Truant proceeded to the Far East. After the Battle of the Java Sea she was one of the last vessels to get away from Surabaya before the Japanese occupation. In December 1942 she returned to Britain for refit. She is here seen in Holy Loch on the Clyde after her 2½ years abroad. Recently she has been used for experimental work, and is expected to be scrapped in the near future.