This is a gun from the German outpost boat "Dirk von Minden." This little ship left Borkum on November 29, 1917, in convoy with the three submarines UB-61, UB-64 and UB-75 and the minelayer UC-49. During heavy storms, which prevented the ships from using their minesweeping equipment, the UB-61 ran into a mine above Terschelling at nine o'clock in the evening. The submarine perished with all hands. The "Dirk von Minden" still tried to offer help, but then also hit a mine itself and went down. Nine of the 22 crew members could be saved.