Type UC III minelaying submarines were used by the Imperial German Navy (German: Kaiserliche Marine) during World War I. They displaced 4740NaN0 at the surface and 5710NaN0 submerged, carried guns, 7 torpedoes and up to 14 mines. The ships were double-hulled with improved range and sea-keeping compared to the UC II type. The type had better seagoing, maneuvering and turning capabilities than its predecessor, while underwater stability was reduced.
A total of 113 Type UC III submarines were ordered by the Imperial German Navy, but only 25 U-boats were completed before the Armistice with Germany in 1918. Of those, 16 U-boats actually served in the war. 54 building orders were cancelled in 1918, while 34 U-boats were never completed and broken up in the ship yards.
German Type UC III submarines had a displacement of 491t when at the surface and 571t while submerged. They had a length overall of 56.51m (185.4feet), a beam of 5.54m (18.18feet), and a draught of 3.77m (12.37feet). The submarines were powered by two six-cylinder four-stroke diesel engines each producing 300PS (a total of 600PS), two electric motors producing 770PS, and two propeller shafts. They had a dive time of 15 seconds and were capable of operating at a depth of .
The submarines were designed for a maximum surface speed of and a submerged speed of . When submerged, they could operate for at ; when surfaced, they could travel at . UC III-class boats were fitted with six 100cm (00inches) mine tubes, fourteen UC 200 mines, three 50cm (20inches) torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 10.5sp=usNaNsp=us SK L/45 or 8.8sp=usNaNsp=us Uk L/30 deck gun. Their complement was twenty-six crew members.
There were 16 Type UC III submarines serving with the Imperial German Navy during World War I.