The submarine was powered by two MWM RS 127 S four-stroke, six-cylinder diesel engines of 700 metric horsepower (510 kW; 690 shp) for cruising, two Siemens-Schuckert PG VV 322/36 double-acting electric motors producing a total of 460 metric horsepower (340 kW; 450 shp) for use while submerged.

The U-boat was not laid down until 11 March 1935, and launched on 29 June 1935, within weeks of the Anglo-German Naval Agreement, which granted Germany parity with the British Empire in submarines.

On 27 December 1942, at 16:20, off Sochi in the Black Sea, a Soviet minesweeper dropped eight depth charges on the boat, causing minor damage.

The boat was damaged by strafing and a bomb hit made a dent in the pressure hull on port side aft, also wounding the commander, who operated the 20mm AA gun himself, with splinters.

Eleven day later, again in the Black Sea, south of Yalta, depth charges from a Soviet escort caused minor damage.

[2] To serve in the 30th U-boat Flotilla, the submarine was transported in sections along the Danube to the Romanian port of Galați.