HMS Spearfish was a second-batch S-class submarine of the Royal Navy, constructed during the 1930s and completed in 1936. It was the only vessel to bear the name Spearfish. The submarine measured 208 feet 8 inches (63.6 meters) in length, with a beam of 24 feet (7.3 meters) and a mean draught of 11 feet 10 inches (3.6 meters). Displacing 768 long tons (780 tonnes) on the surface and 960 long tons (980 tonnes) when submerged, Spearfish was crewed by approximately 40 officers and ratings. Its design allowed it to operate at a maximum diving depth of 300 feet (91.4 meters). Propulsion was provided by two 775-brake-horsepower diesel engines for surface travel, each linked to a propeller shaft, and electric motors of 650 horsepower for submerged movement. The submarine could reach speeds of 13.75 knots (25.5 km/h) on the surface and 10 knots (19 km/h) submerged. Its operational range was notable, capable of traveling up to 6,000 nautical miles (11,100 km) at 10 knots on the surface, with a submerged range of 64 nautical miles (119 km) at 2 knots. Armament consisted of six 21-inch (533 mm) torpedo tubes located in the bow, with six reload torpedoes, totaling twelve torpedoes. Additionally, Spearfish was equipped with a 3-inch (76 mm) deck gun. Laid down on 23 May 1935 at Cammell Laird's shipyard in Birkenhead and launched on 21 April 1936, the vessel was commissioned on 11 December 1936. Its wartime service began with an incident on 24 September 1939, when it was heavily damaged by German warships off Horns Reef but managed to escape and was repaired by March 1940. Notably, on 11 April 1940, Spearfish torpedoed and damaged the German heavy cruiser Lützow in the Kattegat, and later sank two Danish fishing vessels in May. Its operational career was cut short when, on 1 August 1940, while on patrol off Norway, Spearfish was detected and sunk by the German U-34 submarine, approximately 180 miles west-southwest of Stavanger. Only one crew member, Able Seaman William Pester, survived the sinking and was taken prisoner.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.