SM U-22 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...

. She U-22 was engaged in commerce war as part of the naval warfare

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...

, during the First Battle of the Atlantic.

U-22 had a career of 14 patrols, sinking 43 ships for a total of 46,583 tons. Additionally, she damaged 3 ships totalling 9044 tons, and captured 1 prize worth 1170 tons.

Captain Hashagen was the most successful, sinking 28 of the vessels, the largest being the British passenger steamer California at 5,629 tons. She was sunk 145 miles NWxN3/4N of Cape Villano on 17 Oct 1917.