query: subclass_of type 202 submarine
supports: A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term most commonly refers to a large, crewed vessel. It 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. Used as an adjective in phrases such as "submarine cable", "submarine" means "under the sea". The noun "submarine" evolved as a shortened form of "submarine boat" (and is often further shortened to "sub"). For reasons of naval tradition, submarines are usually referred to as "boats" rather than as "ships", regardless of their size. A wet sub is a type of underwater vehicle (submarine) that does not provide a dry environment for its occupants. Usually, wetsuited scuba divers will ride upon the device (as one would ride a motorcycle or with an opening as in an Olympic bobsled), although it can be designed to fully enclose its occupant(s) to provide lower drag. An enclosed vehicle may provide a dry viewing chamber for the occupant(s). The motive force is an electric motor and usually the power source is an electric battery. The depth and duration at depth is typically limited by the requirements of a scuba diver. A boat is a watercraft of a large range of sizes designed to float, plane, work or travel on water. Small boats are typically found on inland waterways (e.g., rivers and lakes) or in protected coastal areas. However, boats such as the whaleboat were designed for operation from a ship in an offshore environment. In naval terms, a boat is a vessel small enough to be carried aboard another vessel (a ship). Another less restrictive definition is a vessel that can be lifted out of the water. Some definitions do not make a distinction in size, as bulk freighters long on the Great Lakes are called oreboats. For reasons of naval tradition, submarines are usually referred to as 'boats' rather than 'ships', regardless of their size and shape. Ships are generally distinguished from boats based on their larger size, shape and cargo or passenger capacity.  Remotely operated vehicles are vehicles which are controlled by an operator who is not in the vehicle. These can be operated by radio control, or through a cable or line connecting the vehicle to the operators location. A midget submarine (also called a mini submarine) is any submarine under 150 tons. Typically operated by a crew of one or two but sometimes up to 6 or 9, 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 other support staff. A submersible is a small vehicle designed to operate underwater. The term "submersible" is often used to differentiate from other underwater vehicles known as submarines, in that a submarine is a fully autonomous craft, capable of renewing its own power and breathing air, whereas a submersible is usually supported by a surface vessel, platform, shore team or sometimes a larger submarine. In common usage by the general public, however, the word "submarine" may be used to describe a craft that is by the technical definition actually a submersible. There are many types of submersibles, including both crewed and uncrewed craft, otherwise known as remotely operated vehicles or ROVs. Submersibles have many uses worldwide, such as oceanography, underwater archaeology, ocean exploration, adventure, equipment maintenance and recovery, and underwater videography. Watercraft are water-borne vehicles including ships, boats, hovercraft and submarines. Watercraft usually have propulsive capability (whether by sail, oar or engine) and hence are distinct from a simple device that merely floats, such as a log raft. A ship is a large buoyant watercraft. Ships are generally distinguished from boats based on size, shape and cargo or passenger capacity. Ships are used on lakes, seas, rivers, and oceans for a variety of activities, such as the transport of people or goods, fishing, entertainment, public safety, and warfare. Historically, a "ship" was a sailing vessel with at least three square-rigged masts and a full bowsprit. The Type 202 was a short lived class of German submarines . Design of these very small submarines started in 1957 by Ingenieurkontor Lübeck ( IKL ) . It was intended to build 40 Type 202 mini submarines with a six man crew but technical difficulties and doubts about their usefulness reduced them to three , and of those three for trials , to be further reduced to two . The boats were in service only a few months and were scrapped shortly after . They were one of the few military U-Boats not bearing `` U-numbers '' , probably since they were never intended for combat use . Instead they were named after important German engineers in submarine constructions ( like Wilhelm Bauer ) . Hans Techel was built with traditional propeller and rudders ( similar to the Type 205 submarines ) , but Friedrich Schürer had a rotatable Kort nozzle instead .
candidates: archaeology battery boat crew definition electric motor engine entertainment force general line midget submarine motorcycle ocean opening operator own plane power public range sail shape ship submarine submersible team term tradition transport travel type variety vehicle vessel warfare water watercraft word
answer: midget submarine