Germany has commissioned over 1,500 U-boats (German : Unterseeboot) into its various navies from 1906 to the present day. The submarines have usually been designated with a U followed by a number, although World War I coastal submarines and coastal minelaying submarines used the UB and UC prefixes, respectively. When Germany resumed building submarines in the 1930s, the numbering of the submarines was restarted at 1. The renumbering was restarted at 1 a third time when Germany resumed building submarines in the 1960s.
There were some 380 U-boats commissioned into the Kaiserliche Marine in the years before and during World War I. Although the first four German U-boats—U-1, U-2, U-3, and U-4—were commissioned before 1910, all four served in a training capacity during the war. German U-boats used during World War I were divided into three series. The U designation was generally reserved for ocean-going attack torpedo U-boats. The UB designation was used for coastal attack U-boats, while the UC designation was reserved for coastal minelaying U-boats.
U-boats designed primarily for deep water service were designated with a U prefix and numbered up to 167.
The Type U 66 submarines were originally constructed for Austro-Hungary as the U-7 class, but were sold to Germany at the start of WWI.
Coastal attack torpedo U-boats were smaller craft intended for operation closer to land. They were designated with a UB prefix and numbered up to 155.
Coastal minelaying U-boats were smaller vessels intended to mine enemy harbors and approaches. They were designated with a UC prefix and numbered up to 114.
Thirty-five Type UC III submarines were planned, but only 25 were completed. Nine of these (UC-106 to UC-114) were never commissioned and were awarded to the United Kingdom and France and broken up in 1921. Ten of these (UC-80 to UC-89) were broken up at yard
At the outbreak of World War I Germany took charge of a number of submarines under construction in German shipyards for other countries.
In the World War II era, Germany commissioned some 1,250 U-boats into the Kriegsmarine.
Originally intended as long-range minelayers, the Type X were later used as long-range cargo transports.
The Type XI was a planned artillery boat, armed with four 128-mm guns in two twin turrets along with an Arado Ar 231 floatplane. Four boats were laid down in 1939 but were cancelled at the outbreak of WWII.
The Type XIV submarine was a shortened version of the Type IXD and used as tankers. Twenty-four were planned, but only 10 were commissioned; three (U-491 to U-494) were cancelled before completed and eleven were never laid down. This type was nicknamed Milchkuh (milk cow).
Twelve Type XVIIB submarines were planned, but only three were completed; three were cancelled at the end of the war before completion and six were cancelled in favor of the Type XXI submarine.
The Type XVIII was a projected attack boat using the Walter propulsion system. Two boats were laid down in 1943, but construction was cancelled in March 1944.
The range of U-5000 to U-6442 was specifically allocated to German midget submarines. The following Seehund Type XXVIIB U-boats were entered into the Kriegsmarine registry as commissioned vessels
Germany captured and commissioned 14 submarines from six countries into the Kriegsmarine during World War II.
The Type UB III submarine was a class of U-boat built during World War I by the German Imperial Navy.
The Type UB I submarine was a class of small coastal submarines (U-boats) built in Germany at the beginning of the First World War. Twenty boats were constructed, most of which went into service with the German Imperial Navy Boats of this design were also operated by the Austro-Hungarian Navy and the Bulgarian Navy. In the Austro-Hungarian Navy, it was called the U-10 class.
The Austro-Hungarian U-boat fleet was created in the decade prior to the First World War. They were built to a variety of designs, many under licence from Germany. They served throughout the war against Italian, French and British shipping in the Mediterranean Sea with some success, losing eight of the twenty eight boats in service in return. They were reinforced by the Imperial German Navy’s Pola Flotilla, mainly comprising coastal U-boats transported by rail from Germany's northern shipyards to the Austrian ports on the Adriatic Sea. Following the end of the war in 1918, all Austrian submarines were surrendered to the Entente powers, who disposed of them individually. As both Austria and Hungary became landlocked in the aftermath of the war, no Austrian or Hungarian submarines have been commissioned since.
U-36 may refer to one of the following German submarines:
U-6 may refer to one of the following German submarines:
U-7 may refer to one of the following submarines:
U-31 may refer to one of the following German submarines:
U-4 may refer to one of the following German submarines:
U-3 may refer to one of the following German submarines:
SM U-10 or U-X was the lead boat of the U-10 class of submarines for the Austro-Hungarian Navy during World War I. She was originally a German Type UB I submarine commissioned into the German Imperial Navy as SM UB-1.
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. A total of fifteen boats were built. The class is sometimes also referred to as the UC-1 class after SM UC-1, the class leader. The Italian X-class submarine was a reverse-engineered and modified type of the UC-1-class.
SM UB-9 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. UB-9 was ordered in October 1914 and was laid down at the AG Weser shipyard in Bremen in November. UB-9 was a little under 28 metres (92 ft) in length and displaced between 127 and 141 tonnes, depending on whether surfaced or submerged. She carried two torpedoes for her two bow torpedo tubes and was also armed with a deck-mounted machine gun. She was launched and commissioned as SM UB-9 in February 1915.
SM UB-11 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. UB-11 was ordered in October 1914 and was laid down at the AG Weser shipyard in Bremen in November. UB-11 was a little under 28 metres (92 ft) in length and displaced between 127 and 141 tonnes, depending on whether surfaced or submerged. She carried two torpedoes for her two bow torpedo tubes and was also armed with a deck-mounted machine gun. She was launched and commissioned as SM UB-11 in March 1915.
SM UB-3 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. She disappeared on her first patrol in May 1915, and was the first of her class to be lost.
SM UB-8 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. She was sold to Bulgaria in 1916 and renamed Podvodnik No. 18, and was the first ever Bulgarian submarine.
SM UC-92 was a German Type UC III minelaying submarine or U-boat in the German Imperial Navy during World War I.
Type UC III minelaying submarines were used by the Imperial German Navy during World War I. They displaced 474 tonnes at the surface and 571 t submerged, carried guns, 7 torpedoes and up to 14 mines. The ships were double-hulled with improved range and sea-keeping compared to the UC II type. The type had better seagoing, maneuvering and turning capabilities than its predecessor, while underwater stability was reduced.
SM UB-106 was a German Type UB III submarine or U-boat in the German Imperial Navy during World War I. She was commissioned into the German Imperial Navy on 7 February 1918 as SM UB-104.
A coastal submarine or littoral submarine is a small, maneuverable submarine with shallow draft well suited to navigation of coastal channels and harbors. Although size is not precisely defined, coastal submarines are larger than midget submarines, 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.