A mine claimed the German U-boat UB-31 and all twenty-seven of her crew in the Strait of Dover on May 2,
1918. Built at Blohm & Voss in Hamburg and commissioned on March 24, 1916 the first victim of this boat was
the 1,866 ton Kittiwake of the Cork Steamship Company Ltd. on April 9, 1917. A little more than a year later on
April 25, 1918 the French ship Joseph became the last victim. A small target of only 42 tons, but it brought the
total of Allied shipping sunk to over 75,000 tons, a further 27,000+ tons of shipping were damaged.

The largest ship sunk by the UB-31 was the 12,358 ton P&O liner Medina on April 28, 1917. Oberleutnant zur
See Thomas Bieber, her second commander, sank 25 of the 28 ships sunk by the UB-31, but he was replaced by
Oberleutnant zur See S. d. Res Wilhelm Braun on Feb. 1, 1918. Bieber went on to command the UB-104 in
July 1918 and sank another 15,000+ tons of Allied shipping. His boat went missing with all hands in Sept. 1918.

Wilhelm Braun had come from the UB-12, a boat he commanded from Sept. 24, 1917 to Mar. 9, 1918 with no
combat victories. His record on the UB-31 was not much better, sinking only three small ships totaling 590
tons before his boat was lost.