4th U-Flotilla

Formed: May 1941. 

Surrendered: May 1945.

Base: Stettin.

Training Tasks: Final fitting out of new boats and working up exercises prior to combat posting. 

Commanders:
   Kapitänleutnant Werner Jacobsen (May 1941 to July 1941)
    Kapitänleutnant Fritz Frauenheim (July 1941 to Augsut 1941)
    Kapitänleutnant Werner Jacobsen (August 1941)
    Fregattenkapitän Heinz Fischer (Augsut 1941 to May 1945)