SM U-72 was one of 329 submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s serving in the Imperial German Navy (Kaiserliche Marine

Kaiserliche Marine

The Imperial German Navy was the German Navy created at the time of the formation of the German Empire. It existed between 1871 and 1919, growing out of the small Prussian Navy and Norddeutsche Bundesmarine, which primarily had the mission of coastal defense. Kaiser Wilhelm II greatly expanded...

) in World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. U-72 was engaged in the commerce war

Naval warfare of World War I

Naval warfare in World War I was mainly characterized by the efforts of the Allied Powers, with their larger fleets and surrounding position, to blockade the Central Powers by sea, and the efforts of the Central Powers to break that blockade or to establish an effective blockade of the United...

 in First Battle of the Atlantic.

Operations

U-72 left the stocks at Hamburg (AG Vulcan) in March 1916, joined the Kiel School, and first entered North Sea on 11 April 1916. Attached 1st Half Flotilla, under the command of Kaptlt. Krafft.

• 15–21 April 1916. Cruise in North Sea. Returned with defects.
• 23–2 May 1916. ? Cruise in North Sea.
• 21 June to 4 July 1916. Northabout. Laid mines off Cape Wrath.
• 20 August - ? 15 September 1916. Northabout to Mediterranean. Laid mines off Lisbon, Oran and Cape Blanc. On arriving at Cattaro joined the Pola-Cattaro Flotilla.
• Of U-72s operations in the Mediterranean, little is known after her arrival in September 1916.
• On a cruise from the middle of February 1917 until 6 March 1917, she sank 4 steamers and stopped British hospital ship
  Hospital ship
  A hospital ship is a ship designated for primary function as a floating medical treatment facility or hospital; most are operated by the military forces of various countries, as they are intended to be used in or near war zones....
  
  , Dunluce Castle. She damaged and was later unsuccessfully attacked by armed trawlers.
• U-72 was reported as not having cruised, with the above exception, after January 1917, and was regarded as a lame duck. Indeed of her class, U-71 to U-80 (all minelayer
  Minelayer
  Minelaying is the act of deploying explosive mines. Historically this has been carried out by ships, submarines and aircraft. Additionally, since World War I the term minelayer refers specifically to a naval ship used for deploying naval mines...
  
  s), U-80 was the only boat not continually in dockyard hands. At the end of October 1918, U-72 was blown up
  Scuttling
  Scuttling is the act of deliberately sinking a ship by allowing water to flow into the hull.This can be achieved in several ways—valves or hatches can be opened to the sea, or holes may be ripped into the hull with brute force or with explosives...
  
   at evacuation of Cattaro.