The S-class submarines were designed to patrol the restricted waters of the North Sea and the Mediterranean Sea. The third batch was slightly enlarged and improved over the preceding second batch of the S-class. The submarines had a length of overall, a beam of and a draught of. They displaced on the surface and submerged. The S-class submarines had a crew of 48 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 third-batch boats had a range of at and at submerged. The boats were armed with seven 21-inch torpedo tubes. A half-dozen of these were in the bow and there was one external tube in the stern. They carried six reload torpedoes for the bow tubes for a total of thirteen torpedoes. Twelve mines could be carried in lieu of the internally stowed torpedoes. They were also armed with a 3-inch deck gun. It is uncertain if Spiteful was completed with a Oerlikon light AA gun or had one added later. The third-batch S-class boats were fitted with either a Type 129AR or 138 ASDIC system and a Type 291 or 291W early-warning radar.
Career
Her first war patrol was in the North Atlantic, from 29 December 1943 to 12 January 1944. She returned to Lerwick, in Shetland, where a battery was replaced and a "singing" screw was repaired. She sailed for Ceylon, arriving in April 1944. She was assigned to 8th Flotilla,. She made two patrols, then transited to Fremantle. She sunk a number of Japanese vessels with gunfire, on 30 June, 2 July and 14 December. Another incident involved, when the American ship almost fired upon her, before recognising her as a friendly ship. Spiteful then bombarded installations on the Andaman Islands and Christmas Island. She made three further patrols, totalling 109 days at sea - the three longest patrols by any S-class submarine - 34, 38 and 37 days - with little luck. She returned to the UK in April 1945 for a refit.
