HMS Sturgeon was an S-class submarine that entered service with the Royal Navy in 1932. Ordered in 1930, she was laid down at Chatham Dockyard in January 1931 and launched on 8 January 1932. Commissioned on 27 February 1933, Sturgeon was assigned to the 2nd Submarine Flotilla. At the start of World War II, Sturgeon conducted patrols in the North Sea. On 6 September, she was mistakenly bombed by British aircraft. On her second patrol, she fired three torpedoes at an unidentified submarine, which was in fact her sister ship , but the torpedoes missed. On her third patrol, she missed the German U-boat and was damaged after hitting the bottom, requiring repairs. On 20 November, she sank the German armed trawler with torpedoes. The sinking was the first successful attack by a British submarine of the war, and was a morale boost for British submariners. During her next patrols in the North Sea, Sturgeon sighted and sank several ships, including the German troop transport Pionier and the Danish merchants SS Sigrun and SS Delfinus. Afterwards, Sturgeon patrolled in the Bay of Biscay, acted as a beacon during Operation Torch, then, after being again damaged by Allied aircraft, escorted the Arctic Convoys PQ 15 and PQ 17. Sturgeon was transferred to the 8th Submarine Flotilla, which operated on the Mediterranean Sea, in October 1942 to support the Allied landings in North Africa. In May 1943, she was loaned to the Royal Netherlands Navy as HNLMS Zeehond. Zeehond was returned to the Royal Navy following the war and was sold for scrap in 1946. She was one of the four submarines that formed the First Group of the S class, and the only one of these to survive the war. Design and description The S-class submarines were designed as successors to the L class and were intended to operate in the North and Baltic Seas. The submarines had a length of overall, a beam of and a mean draught of . They displaced on the surface and submerged. The S-class submarines had a crew of 38 officers and ratings. They had a diving depth of . For surface running, the boats were powered by two diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, the first-batch boats had a range of at