WHMS H49 was a British H-class submarine built by William Beardmore and Company, Dalmuir. She was launched on 15 July 1919 and commissioned on 25 October 1919.
WHMS Seahorse was a first-batch S-class submarine built for the Royal Navy during the 1930s. Ordered in March 1931, she was laid down at Chatham Dockyard in September 1931 and launched on 15 November 1932.
WHMS Snapper was a second-batch S-class submarine built during the 1930s for the Royal Navy. Completed in 1935, the boat participated in the Second World War. Snapper is one of the 12 boats named in the song "Twelve Little S-Boats".
WHMS Splendid was a third-batch S-class submarine built for the Royal Navy during World War II. She was laid down on 7 March 1941 and launched on 19 January 1942. After an initial patrol through the Bay of Biscay to Gibraltar, Splendid conducted two patrols in the Mediterranean Sea; one was abandoned after technical problems and on the other she sank two Italian ships. On her next patrol, the submarine attacked two Italian convoys, sinking an Italian destroyer in the second attack. Based in Algiers, the boat operated north of Sicily, sinking six Italian ships, including two tankers and two heavy merchant ships. Splendid was detected by a German destroyer on 21 April 1943 while patrolling off Naples, Italy; the submarine was attacked with depth charges by the destroyer and forced to surface, after which she was scuttled and her surviving crew members taken prisoner. She was the most successful British submarine by tonnage sunk between November 1942 and May 1943.
WHMS Starfish was a first-batch S-class submarine built for the Royal Navy during the 1930s. Completed in 1933, she participated in the Second World War.
WHMS Sterlet was a second-batch S-class submarine built during the 1930s for the Royal Navy. Completed in 1938, the boat fought in the Second World War. The submarine is one of the 12 boats named in the song Twelve Little S-Boats. Thus far she has been the only ship of the Royal Navy to be named Sterlet.
WThe second HMS Tarpon (N17) was a T-class submarine of the Royal Navy. She was laid down by Scotts, Greenock and launched in October 1939. She is named after the large fish Tarpon; one species of which is native to the Atlantic, and the other to the Indo-Pacific Oceans.
WHMS Tigris was a T-class submarine of the Royal Navy. She was laid down at Chatham Dockyard and launched in October 1939.
WHMS Undine was a U-class submarine and lead vessel of her class, which is sometimes called the Undine class as a result. The submarine entered service in 1938. Undine performed war patrols during the Second World War and was scuttled after being damaged by German minesweepers off Heligoland on 7 January 1940.