Canadian war artist Donald Cameron Mackay's painting depicts a gun crew firing on enemy aircraft using a 20mm Oerlikon cannon.

The Swiss-designed Oerlikon, widely used by both Allied and Axis forces during the Second World War, had a higher rate of fire than the 2-pounder pom-poms and had more stopping power than the lighter machine-guns fitted to Royal Canadian Navy's ships. While used as anti-aircraft weapons, as seen here, on a wide range of ships, Oerlikons also proved effective in engagements against surfaced German submarines, keeping enemy crews below decks and away from their own guns.

Anti-Aircraft Gun and Crew in Action
Painted by Donald C. Mackay
Beaverbrook Collection of War Art
CWM 19710261-4197