German submarines using Bordeaux, France as base in 1941

American naval attaché at Rome, Italy reported in February 1941 that 24 German submarines were operating out of Bordeaux, France.

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.