 Built in Hamburg and completed in January 1943, "U-958" was given to "Kapitänleutnant" Gerhard Groth, who remained with the boat for her whole operational lifespan.Earmarked for training duties in the Baltic, "U-958" was based in Kiel and helped prepare other boats for operational service, as well as training up potential commanders and officers and honing tactical and operational techniques.She fulfilled this duty for the whole of 1943, before huge losses in the Battle of the Atlantic forced her to be deployed from Bergen, Norway.