Second World War
Battle of the Atlantic  - Atlantic Battleground

Allied forces, including the Royal Canadian Navy, fought against Axis forces in the battle of the Atlantic over a vast and often dangerous oceanic battlefield. Harbours and bases like Halifax were essential for ships, and commanders on shore planned and coordinated the movements of convoys and anti-submarine forces.

Enigma Machine

The Enigma was a sophisticated German machine for the encryption of messages.

Drawing on Polish expertise and experience, the British first broke the German Navy's Enigma cipher in 1941. This allowed them to read many important messages and to help track the movements of German U-Boats (submarines). Enigma could not always be deciphered, however, because the Germans kept improving the equipment and changing its settings. The German Navy used this 1943 example.

Enigma Encryption Machine Type M4
CWM 19470003-008