The struggle on the Atlantic between Allied navies and German U-Boats (submarines) brought the naval war into Canada, turning the river and Gulf of St. Lawrence into a battleground. From 1942, German U-Boats sank 23 merchant and naval ships; improvements in anti-submarine defences ultimately stemmed these losses.
This 1943 map, providing a general overview of the River and Gulf of St. Lawrence, formed part of a German U-Boat (submarine) navigation handbook.
The legend at the upper left identifies locations including navigation lights and lighthouses (Signalstelle), coastal radio stations (Küstenfunkstelle) and facilities that could help a U-Boat determine its location. It also identifies threats like coastal defence batteries (Küstenbefestigung) and civilian airfields that could serve as bases for Allied military aircraft (Zivilflugplatz).
George Metcalf Archival Collection