A midget submarine is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to six or nine, with little or no on-board living accommodation. They normally work with mother ships, from which they are launched and recovered and which provide living accommodation for the crew and support staff.
HMS Sceptre (P215) was a third-batch S-class submarine built for the Royal Navy during World War II. Completed in April 1943, she spent the majority of her career in the North Sea, off Norway. After an uneventful patrol, the submarine participated in Operation Source, an attack on German battleships in Norway using small midget submarines to penetrate their anchorages and place explosive charges. However, the midget submarine that she was assigned to tow experienced technical difficulties and the mission was aborted. During her next four patrols, Sceptre attacked several ships, but only succeeded in severely damaging one. She was then ordered to tow the submarine X24, which was to attack a floating dry dock in Bergen. The operation, codenamed Guidance, encountered difficulties with the attacking submarine's charts, and the explosives were laid on a merchant ship close to the dock instead. The dock was damaged and the ship sunk, and X24 was towed back to England. Sceptre then conducted a patrol in the Bay of Biscay, sinking two German merchant ships, before being reassigned to tow X24 to Bergen again. The operation was a success, and the dry dock was sunk.
Human torpedoes or manned torpedoes are a type of diver propulsion vehicle on which the diver rides, generally in a seated position behind a fairing. They were used as secret naval weapons in World War II. The basic concept is still in use.
The X class was a World War II midget submarine class built for the Royal Navy during 1943–44. It was substantially larger than the original Chariot manned torpedo.
Britain's commando frogman force is now the Special Boat Service (SBS), whose members are drawn largely from the Royal Marines. They perform various operations on land as well as in the water. Until the late 1990s, all members of the Special Air Service (SAS) Boat Troop were trained as commando frogmen.
Operation Source was a series of attacks to neutralise the heavy German warships – Tirpitz, Scharnhorst and Lützow – based in northern Norway, using X-class midget submarines.
Biber was a German midget submarine of the Second World War. Armed with two externally mounted 53-centimetre (21 in) torpedoes or mines, they were intended to attack coastal shipping. They were the smallest submarines in the Kriegsmarine.
Seehund, also known as Type XXVII, was a midget submarine built by Nazi Germany during World War II. Designed in 1944 and operated by two-man crews, it was used by the Kriegsmarine during the closing months of the war, sinking nine merchant vessels and damaging an additional three, while losing 35 boats, mostly attributed to bad weather. The French Navy used four captured boats after the war until 1953.
HMS Stygian was a S-class submarine of the British Royal Navy, and the only ship so far to bear the name. The boat is listed as being a member of the fourth group, although she had the external stern torpedo tube fitted as in the third group.
Above Us the Waves is a 1955 British war film about human torpedo and midget submarine attacks in Norwegian fjords against the German battleship Tirpitz. Directed by Ralph Thomas, it is based on two true-life attacks by British commando frogmen, first using Chariot manned torpedoes in Operation Title in 1942, and then X-Craft midget submarines in Operation Source in 1943. Filmed at Pinewood Studios, England, with outdoor scenes in Guernsey, some of the original war equipment was used in the film.
HMS Stratagem was a third-batch S-class submarine built for the Royal Navy during World War II. Completed in 1943, she made her first war patrol off Norway before she was sent to the Far East, where she conducted three war patrols. On her second, she shelled installations on a Japanese-held island. Her only success came on her last patrol, when she torpedoed and sank a Japanese oil tanker. Soon after, she was spotted by aircraft and depth charged by a destroyer. She was forced to surface, and was scuttled to prevent her capture. Ten crew members escaped the sinking submarine and were taken prisoner, of whom only three survived the war.
HMS Syrtis was a third-batch S-class submarine built for the Royal Navy during the Second World War. Completed in 1943, Syrtis spent most of her career in the Arctic, off Norway, other than a single patrol in the Bay of Biscay,
HMS Sea Nymph was a S-class submarine of the third batch built for the Royal Navy during World War II. Completed in July 1942, she spent the majority of her career patrolling the waters off Norway in the North Sea, then was sent to the Pacific but was forced back due to technical problems.
Vice-Admiral Sir Arthur Richard Hezlet, nicknamed Baldy Hezlet, was a decorated Royal Navy submariner. He became the Royal Navy's youngest captain at the time – aged 36 – and its youngest admiral, aged 45. In retirement he became a military historian.
The Welfreighter was a Second World War British midget submarine developed by the Special Operations Executive (SOE) for the purpose of landing and supplying agents behind enemy lines. It only saw action once and was not particularly successful.
The Motorised Submersible Canoe (MSC), nicknamed Sleeping Beauty, was built by the British Special Operations Executive (SOE) during World War II as an underwater vehicle for a single frogman to perform clandestine reconnaissance or attacks against enemy vessels.
John Robert Vernon Dolphin was a British engineer and inventor, who joined the Secret Intelligence Service and then became the Commanding Officer of the top-secret Second World War Special Operations Executive (SOE) "Station IX", where specialist military equipment was developed. During his time there his inventions included the Welman submarine and the Welbike.
The Chariot was a British manned torpedo used in World War II. The Chariot was inspired by the operations of Italian naval commandos, in particular the raid on 19 December 1941 by members of the Decima Flottiglia MAS who rode "Maiali" manned torpedoes into the port of Alexandria and there placed limpet mines on or near the battleships HMS Valiant and HMS Queen Elizabeth as well as an 8,000-ton tanker, causing serious damage which put both battleships out of operational use until 1943.
Captain William Richmond Fell, was a New Zealand naval officer. He served in the Royal Navy, mainly in submarines, and was involved in the development of human torpedoes and midget submarines during the Second World War.
Operation Title was an unsuccessful Allied attack on the German battleship Tirpitz during World War II. It involved two British Chariot manned torpedos that were transported close to the battleship's anchorage in Trondheimsfjorden, Norway, by a Norwegian trawler between 26 and 31 October 1942.
United Kingdom Special Operations Executive 
