[Note 1] In seven patrols UC-51 was credited with sinking 28 ships, either by torpedo or by mines laid.

[1] The wreck was located and identified by marine archaeologist Innes McCartney close to the official sinking position in 2001.

She had a dive time of 48 seconds and was capable of operating at a depth of 50 metres (160 ft).

When submerged, she could operate for 56 nautical miles (104 km; 64 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,820 to 9,450 nautical miles (16,330 to 17,500 km; 10,150 to 10,870 mi) at 7 knots (13 km/h; 8.1 mph).

UC-51 was fitted with six 100 centimetres (39 in) mine tubes, eighteen UC 200 mines, three 50 centimetres (20 in) torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8 cm (3.5 in) Uk L/30 deck gun.