Russian submarines used Polyarnoe as base in April 1943

American naval attaché at Moscow, Russia reported in April 1943 referring to a statement of vice admiral Golovko, commander-in-chief of the Russian Northern Fleet that 20 submarines were operating out of Polyarnoe with an average of 8 on station.

Source

National Archives USA. Record Group 38: Records of the Office of the Chief of Naval Operations. Series: Secret Naval Attaches Reports. Estimate of potential military strength (pt.). Summaries. Reports from London, Paris, Brussels, Rome and Berlin. Roll M975-001.