SM UB-27 was a German Type UB II

German type UB II submarine

The UB II type submarine was a class of U-boat built during World War I by the Kaiserliche Marine. They were enlarged from the preceding type UB I and were more effective vessels. The boats were a single hull design with a 50 metre maximum diving depth and a 30-45 second diving time...

 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...

 or U-boat

U-boat

U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

 in the German Imperial Navy  during 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...

. The U-boat was ordered on 30 April 1915 and launched on 20 December 1915. She was commissioned into the German Imperial Navy on 23 February 1916 as SM UB-27."SM" stands for "Seiner Majestäts" (His Majesty's) and combined with the U for Unterseeboot would be translated as "His Majesty's Submarine". She sank 12 ships in 17 patrols.

On 29 April 1916 in the North Sea about 15 miles (24.1 km) south-east of Souter Point near Whitburn

Whitburn, South Tyneside

Whitburn is a village in South Tyneside, on the coast of North East England. It lies just to the north of the City of Sunderland in the ceremonial county of Tyne and Wear. Until 1974, when the Local Government Act 1972 came into being, it was part of County Durham...

, County Durham

County Durham

County Durham is a ceremonial county and unitary district in north east England. The county town is Durham. The largest settlement in the ceremonial county is the town of Darlington...

, SM UB-27 opened with her deck gun fire at SS Wandle, an 889 GRT

Gross Register Tonnage

Gross register tonnage a ship's total internal volume expressed in "register tons", one of which equals to a volume of . It is calculated from the total permanently enclosed capacity of the vessel. The ship's net register tonnage is obtained by reducing the volume of non-revenue-earning spaces i.e...

 "flat-iron" collier of the Wandsworth, Wimbledon and Epsom District Gas Company

Wandsworth and District Gas Company

The Wandsworth and District Gas Company was a maker and distributor of coal gas in south-west London from 1834 until 1949.-History:The Wandsworth gasworks was built in 1834 on the Surrey bank of the River Thames near Wandsworth Bridge. Its supplied Wandsworth, Putney and part of Battersea...

. The collier engaged the submarine and survived. Afterwards in Britain it was believed Wandle had sunk UB-27 and the master

Captain (nautical)

A sea captain is a licensed mariner in ultimate command of the vessel. The captain is responsible for its safe and efficient operation, including cargo operations, navigation, crew management and ensuring that the vessel complies with local and international laws, as well as company and flag...

, G.E.A. Mastin, and his crew were celebrated.

UB-27 disappeared after 22 July 1917. reported ramming and depth charging

Depth charge

A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...

a U-boat on 29 July 1917. A postwar German study concluded that it was possible that Halcyon sank UB-27.