Between November 1942 and February 1943, "Seadog" conducted three patrols off Norway, protecting Arctic convoys to and from Northern Russia, but did not sight any potential targets. After her first patrol, the boat was commanded by Desmond Martin. Returning from these operations, the submarine docked in Ardrossan to have a Oerlikon light anti-aircraft gun added aft of the conning tower and additional equipment installed.