[Note 1] UB-27 sank 11 ships in 17 patrols for a total of 18,091 gross register tons (GRT).

The submarine was powered by two Benz six-cylinder diesel engines producing a total 270 metric horsepower (270 shp; 200 kW), two Siemens-Schuckert electric motors producing 280 metric horsepower (210 kW; 280 shp), and one propeller shaft.

She had a complement of twenty-one crew members and two officers and a thirty-second dive time.

[2] On 29 April 1916 in the North Sea about 15 nautical miles (28 km; 17 mi) south-east of Souter Point near Whitburn, County Durham, UB-27 opened with her deck gun fire at SS Wandle, an 889 GRT "flat-iron" collier of the Wandsworth, Wimbledon and Epsom District Gas Company.

HMS Halcyon reported ramming and depth charging a U-boat on 29 July 1917.