 Her construction was rapid and smooth, and following her completion in February 1943 she was taken for training and working-up patrols in the Baltic Sea and off the Norwegian coast.Her commander during this period was veteran submariner "Kapitänleutnant" Emmo Hummerjohann, who was experienced in combat operations and was still in charge when she departed Bergen, Norway in early October 1943 for her maiden combat patrol in the North Atlantic.German Type VIIC submarines were preceded by the shorter Type VIIB submarines.