A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as "boats" rather than "ships" irrespective of their size.
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare role and enforcing a naval blockade against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and other parts of the British Empire, and from the United States, to the United Kingdom and to the Soviet Union and the Allied territories in the Mediterranean. German submarines also destroyed Brazilian merchant ships during World War II, causing Brazil to declare war on both Germany and Italy on 22 August 1942.
The Type A Ko-hyoteki class was a class of Japanese midget submarines (Kō-hyōteki) used during World War II. They had hull numbers but no names. For simplicity, they are most often referred to by the hull number of the mother submarine. Thus, the midget carried by I-16-class submarine was known as I-16's boat, or "I-16tou."
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.
Air-independent propulsion (AIP), or air-independent power, is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen. AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels.
Seeteufel was a two-man amphibious midget submarine, developed by Nazi Germany during World War II. Only one prototype was built in 1944, although its testing was relatively successful and negotiations began for another series of three to test the necessary changes before beginning series production in 1945. These plans were cancelled at the beginning of that year when the decision was made to concentrate production on designs already being built.
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.
Beginning in ancient times, mankind sought to operate under the water. From simple submersibles to nuclear submarines, humans have searched for a means to remain safely underwater to gain the advantage in warfare, resulting in the development of the submarine.
Seehund, also known as Type XXVII, was a midget submarine manufactured 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.
Hai (shark) was an advanced model of the Marder-class midget submarines created in Nazi Germany during World War II and operated by the K-Verband. Its prototype performed poorly during test runs and therefore no other boats were produced.
The S-class or Srednyaya submarines were part of the Soviet Navy's underwater fleet during World War II. Unofficially nicknamed Stalinets, boats of this class were the most successful and achieved the most significant victories among all Soviet submarines. In all, they sank 82,770 gross register tons (GRT) of merchant shipping and seven warships, which accounts for about one-third of all tonnage sunk by Soviet submarines during the war.
German submarine U-259 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 25 March 1941 at the Bremer Vulkan yard at Bremen-Vegesack, launched on 30 December 1941, and commissioned on 18 February 1942 under the command of Kapitänleutnant Klaus Köpke. After training with the 5th U-boat Flotilla at Kiel, U-259 was transferred to the 3rd U-boat Flotilla, based at La Pallice, France, for front-line service from 1 September 1942.
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.
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.
Hecht, also known as Type XXVIIA, was a two-man all-electric German midget submarine created during World War II.
The CB class was a group of midget submarines built for the Italian Navy during World War II. However, they were also used by several other navies, seeing action in the Mediterranean and in the Black Sea.
M24 Japanese Midget Submarine wreck site is a heritage-listed former midget submarine and now archaeological site located in unincorporated waters off Sydney's Northern Beaches in New South Wales, Australia. The Ko-hyoteki-class midget submarine was designed by the Japanese Imperial Navy and built from 1941 to 1942 by Kure Naval Yard or Ourazaki Naval Yard. The site was added to the New South Wales State Heritage Register on 7 December 2007.
