 Farnborough stopped , blew off steam , and launched a boat to simulate a surrender . As U @-@ 68 closed to 800 yards ( 730 m ) , Farnborough raised the White Ensign , uncovered her guns and opened fire with three of her five 12 pounder ( 76 mm ) guns . The British gunners scored several hits on the U @-@ boat out of 21 rapidly fired rounds . As U @-@ 68 began to sink , Campbell steered Farnborough over U @-@ 68 's location and dropped a depth charge that blew the bow of the submarine out of the water . As U @-@ 68 began going down by the stern , Farnborough 's gunners scored another five hits on the U @-@ boat 's conning tower . U @-@ 68 sank with the loss of all 38 men at position 51 ° 54 ′ N 10 ° 53 ′ W off Dingle in southern Ireland . U @-@ 68 sank no ships during her brief service career . 
