The Type UC I coastal submarines were a class of small minelaying U-boats built in Germany during the early part of World War I.

These submarines were designed by Dr. Werner of the Torpedo Inspectorate, and based on the Type UB I small coastal submarines, with a revised bow section housing inclined minelaying tubes and uprated engines to compensate for the increased displacement and less streamlined form.

They were constructed very quickly, and suffered from problems with their minelaying system, which in some cases caused the mines to become armed before exiting their tubes and explode prematurely.

The submarines were powered by one Daimler-Motoren-Gesellschaft or Benz six-cylinder, four-stroke diesel engine producing 80–90 metric horsepower (59–66 kW; 79–89 shp), an electric motor producing 175 metric horsepower (129 kW; 173 shp), and one propeller shaft.

When submerged, they could operate for 50 nautical miles (93 km; 58 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, they could travel 780–910 nautical miles (1,440–1,690 km; 900–1,050 mi) at 5 knots (9.3 km/h; 5.8 mph).