U-boat

U-boats were submarines used by the Germans in the 20th century.

World War I
During World War I, a German U-boat, the U-20, sank the RMS Lusitania on 7 May 1915, which precipitated the entry into the United States of America into the First World War. (AUDIO: The Sirens of Time)

In July 1915, the U-29 transported Victor von Stein and Ingrid Karnstein to Haiti. (PROSE: White Darkness)

In 1917, the Eleventh Doctor, Edward Anderson and Lord Hellcombe escaped in a U-boat and fired a torpedo to damage a Dalek flying saucer underwater. It was damaged by Aqua-Daleks. (COMIC: The Dalek Project)

World War II
In World War II, a German U-boat patrolling the English Channel in 1943 was sent forward in time to October 1964, where it threatened to torpedo the Isle of Wight ferry. Sir Toby Kinsella of the Intrusion Counter-Measures Group ordered Group Captain Ian Gilmore and his squad to investigate and render assistance to the personnel of the nearby Lanchester Naval Base. (AUDIO: State of Emergency)

At some point during the war, Jack Harkness claimed to have been kept as a prisoner of war aboard a German U-boat for a number of weeks. He later told Ianto Jones that he had seduced a number of the sailors, and Ianto then corrected him by saying they were called submariners. (PROSE: Plant Life)

Another U-boat sank the ship on which Alfred Beadle served. (PROSE: Nightshade)

At some point, Alec Palmer was involved in operations in the North Sea to disrupt U-boats. (TV: Hide)

Later history
U-147 was among the various ships captured by the Daleks. Its crew was brainwashed and the U-boat took part in the Daleks' raid on Sydney Harbour during the 1970s. (COMIC: *Sub Zero)