A coastal submarine or littoral submarine is a small, maneuverable

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

with a shallow

draft Draft, the draft, or draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a v ...

well suited to navigating coastal channels and harbors. Although size is not precisely defined, coastal submarines are larger than

midget submarine 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 an ...

s, but smaller than sea-going submarines designed for longer patrols on the open ocean. Space limitations aboard coastal submarines restrict fuel availability for distant travel, food availability for extended patrol duration, and number of weapons carried. Within those limitations, however, coastal submarines may be able to reach areas inaccessible to larger submarines, and be more difficult to detect.

History

The earliest submarines were effectively coastal submarines, but as modern submarine tactics developed during

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

, the advantages of rapid construction and portability encouraged the development of UB

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such ...

launching, and UC minelaying coastal submarines in 1915 to operate in the

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

. These coastal submarines displaced only 15 to 20 percent of the weight of a contemporary conventional U-boat, could be built in one-quarter of the time it took to complete a conventional U-boat, and be delivered on railway wagons to operating bases in

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

. Improved versions of UB and UC coastal submarines were devised. Total production of German coastal submarines during World War I was 136 type UB and 95 type UC. U-9 IWM HU 1012

German submarine construction between the World Wars began in 1935 with the building of 24 Type II coastal submarines. These coastal U-boats, with another eight completed prior to hostilities, made

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

combat patrols during the early months of

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

and then served in the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

training crews to operate ocean-going submarines. The 30th U-boat Flotilla of six Type II U-boats was transported overland via the

Autobahn The (; German , ) is the federal controlled-access highway system in Germany. The official term is (abbreviated ''BAB''), which translates as 'federal motorway'. The literal meaning of the word is 'Federal Auto(mobile) Track'. Much of t ...

and then down the

Danube The Danube ( ; see also #Names and etymology, other names) is the List of rivers of Europe#Longest rivers, second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest sou ...

for combat patrols in the

Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...

until September 1944.

Examples

* German Type UB I submarine *

German Type UB II submarine The UB II type submarine was a class of U-boat built during World War I by the German Imperial Navy. They were enlarged from the preceding type UB I and were more effective vessels. The boats were a single hull design with a 50-metre maximum di ...

German Type UB III submarine The Type UB III submarine was a class of U-boat built during World War I by the German Imperial Navy. Design UB III boats carried 10 torpedoes and were usually armed with either an 8.8 cm SK L/30 naval gun, or a 10.5 cm SK L/45 naval gun, deck ...

German Type UC I submarine The Type UC I coastal submarines were a class of small minelaying U-boats built in Germany during the early part of World War I. They were the first operational minelaying submarines in the world (although the Russian submarine Krab (1912), Russ ...

* German Type UC II submarine *

German Type UC III submarine Type UC III minelaying submarines were used by the Imperial German Navy () during World War I. They displaced at the surface and submerged, carried guns, 7 torpedoes and up to 14 mines. The ships were double-hulled with improved range and sea ...

* British H-class submarine * German Type II submarine * *

German Type XVII submarine The Type XVII U-boats were small coastal submarines that used a high-test peroxide propulsion system, which offered a combination of air-independent propulsion and high submerged speeds. Background In the early 1930s Hellmuth Walter had designe ...

* Type XXIII submarine * Ha-201-class submarine *

Type 201 submarine The Type 201 was Germany's first U-boat class built after World War II. Design They were built out of amagnetic steel to counter the threat of magnetic naval mines, but the material had been insufficiently tested and proved to be problemati ...

Type 205 submarine The Type 205 was a class of Germany, German diesel-electric submarines. They were single-hull (watercraft), hull vessels optimized for the use in the shallow Baltic Sea. The Type 205 is a direct evolution of the Type 201 submarine, Type 201 class ...

* Type 206 submarine * Sang-O-class submarine * STM 500 * Gotland-class submarine * Fateh-class submarine * Andrasta-class submarine

Notes

Sources

* * * {{Warship types of the 19th & 20th centuries Submarines by type

History

Examples

See also

Notes

Sources