A submarine is a watercraft capable of independent operation underwater. The term "submarine" is also sometimes used historically or informally to refer to remotely operated vehicles and robots, or to
US Virginia-class submarine underway in Groton, Connecticut, July 2004
Russian Akula-class submarine of the Northern Fleet, in 2008
An early submersible craft, built by Cornelis Drebbel, propelled by oars
Cutaway replica of Bushnell's "Turtle" at the Submarine Force Library and Museum, Groton, Connecticut
U-boats are naval submarines operated by Germany, especially during World War I and World War II. The term is an anglicized form of the German word U-Boot, a shortening of Unterseeboot. Austro-Hungari
Submarine
…Som was fired upon by Japanese torpedo boats, but then withdrew. Military submarines first made a significant impact in World War I. Forces such as the U-boats of Germany saw action in the First Battle of the Atlantic, and were responsible for sinking RMS Lusitania, which was sunk as a result of unrestricted…
U-995, a typical VIIC/41 U-boat on display at the Laboe Naval Memorial near Kiel, Germany
The first German submarine, the SM U-1. Her remains are on display at the Deutsches Museum in Munich.
The German submarine U-11, showing the kerosene vapour trail.
Sea mines are loaded in a UC coastal submarine in the harbour of Zeebrugge