The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 shaft horsepower (1,010 PS; 750 kW) for use while submerged.

About three months later she was commissioned into service under the command of Oberleutnant zur See Friedrich-Wilhelm Marienfeld (Crew X/38) in the 31st U-boat Flotilla on 22 December 1943.

Stopping briefly in Bergen, Norway, for replenishment, she experienced engine troubles in the Norwegian Sea and had to return to port.

She set off again on 12 October from Bergen and operated in the Gulf of St. Lawrence sinking one warship, HMCS Shawinigan in the Cabot Strait on the night of 24 November 1944.

[3] All of Shawinigan's 90 crew members were lost, seven officers and 83 ratings including able seaman Dudley "Red" Garrett, a former Toronto Maple Leafs National Hockey League player.