[Note 1] Mines laid by UC-3 in her 29 patrols were credited with sinking 22 ships and damaging 2 others.

The submarine was powered by one Daimler-Motoren-Gesellschaft six-cylinder, four-stroke diesel engine producing 90 metric horsepower (66 kW; 89 shp), an electric motor producing 175 metric horsepower (129 kW; 173 shp), and one propeller shaft.

When submerged, she could operate for 50 nautical miles (93 km; 58 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 780 nautical miles (1,440 km; 900 mi) at 5 knots (9.3 km/h; 5.8 mph).

She was built by AG Vulcan Stettin and her complement was fourteen crew members.

UC-3's fate have different version: One is on 23 April 1916 she was detected using a hydrophone, trapped in a net, and then quickly sunk after a large explosion.