Two months later, on 13 August 1917, she was sunk in the Atlantic west of the harbour of Killybegs by the German submarine U-84, commanded by Walter Rohr. His war diary describes how he sighted a lone merchant ship, with no defensive armament (an unusual sight by 1917). Bergamot evidently sighted the U-boat's periscope, as she began to zig-zag at high speed. U-84 fired one torpedo — which hit — and Bergamot sank in 4 minutes. Surfacing, U-84 sighted an unusually large number of crew (70) and pieces of wood floating. The U-boat's log identifies the possibility of Bergamot being a "trap ship".