First World War (1914-1918)
The U-Boat Menace

The emergence of the submarine was a major development in naval warfare. German submarine - or U-Boat - attacks against Allied shipping in the Atlantic and in European waters posed a major threat to the Allied war effort.

First World War Atlantic Convoy

This photograph shows six merchant ships in a First World War Atlantic convoy.

In response to increasing merchant ship losses caused by German U-Boats (submarines), the British Admiralty introduced convoys in 1917. By grouping together merchant ships and providing them with escorting warships, the U-Boats' task of finding and sinking ships was made much harder, and Allied shipping losses fell significantly. This photograph was likely taken by Sub-Lieutenant Arthur Rankin, the navigation officer aboard HMCS Canada, which helped escort convoys off Canada's east coast.

George Metcalf Archival Collection
CWM 20080041-027