German submarines more active in the Mediterranean in November 1941

American naval attaché at Rome, Italy reported in November 1941 a pronounced increase of German submarine activities in the Mediterranean.

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.