"Polarlys" was in Bergen on 9 April 1940 when the Germans captured the town and was soon taken over by the "Kriegsmarine" for use as an accommodation ship. They painted the name "Satan" on the ship, but was later changed to simply "Tan". She was returned to her owners in December 1940, but was requisitioned by the Germans once again in October and November 1944 for use as a troop transport as they retreated from northern Norway. In March 1945, the ship laid up at Stamnes in the Osterfjord and remained there until the end of the war in Europe.