SM UB-31
Date Name Nationality Tonnage Fate
9 April 1917 Kittiwake United Kingdom 1,866 Sunk
24 April 1917 Saint Jacques France 415 Damaged
28 April 1917 Medina United Kingdom 12,350 Sunk
21 May 1917 City of Corinth United Kingdom 5,870 Sunk
15 June 1917 Teesdale United Kingdom 2,470 Damaged
17 June 1917 Stanhope United Kingdom 2,854 Sunk
5 July 1917 Ocean Swell United Kingdom 195 Sunk
6 July 1917 Ariadne Christine United Kingdom 3,550 Damaged
7 July 1917 Bellucia United Kingdom 4,368 Sunk
10 July 1917 Hildegard United States 622 Sunk
11 July 1917 Brunhilda United Kingdom 2,296 Sunk
1 August 1917 Alcyone United Kingdom 149 Sunk
1 August 1917 Laertes United Kingdom 4,541 Sunk
2 August 1917 Newlyn United Kingdom 4,019 Sunk
3 August 1917 Renee Marthe France 50 Sunk
8 August 1917 Algerie France 3,386 Damaged
8 September 1917 Elizabeth United Kingdom 58 Sunk
9 September 1917 Pluton Norway 1,449 Sunk
19 October 1917 Waikawa United Kingdom 5,666 Sunk
20 October 1917 Colorado United Kingdom 7,165 Sunk
Summary of raiding history
SM UB-31 was a German Type UB II submarine or U-boat in the German Imperial Navy () during World War I. The U-boat was ordered on 22 July 1915 and launched on 16 November 1915. She was commissioned into the German Imperial Navy on 25 March 1916 as SM UB-31. The submarine sank 26 ships in 25 patrols. UB-31 was depth charged and sunk by British warships , , and in the English Channel on 2 May 1918. Alternatively she may have been sunk by a mine on that date.