Source
Gold bars

A shipment of fish that arrived in Halifax harbour on July 1, 1940 was classified top-secret. What could be so special about a load of fish? "Fish" was actually the code name for a cargo consisting of Britain's gold reserves and priceless securities.

During the Second World War, Britain's wealth was secretly packed in crates and shipped across the Atlantic Ocean. Given the number of German U-boats ready to sink whatever crossed their paths, doing so was a huge gamble. The valuables were sent in several shipments and each reached its destination safely. The gold ingots and coins were kept for the duration of the war in the Bank of Canada's vaults on Wellington Street in Ottawa. The securities were locked in an underground vault three stories beneath the Sun Life Assurance Company building in Montreal and guarded by Royal Canadian Mounted Police officers around the clock. The 5,000 Sun Life employees never knew what was stored away beneath them.

Although hundreds of people were involved in the operation, not a single piece of the cargo went missing. And although no one was required to give an oath of secrecy, no information was ever leaked.

Source Sun Life Building, Montréal, Quebec, around 1931	Source Entrance of the Sun Life Building, Montréal, Quebec, 1933

References

Draper, Alfred. Operation Fish. Markham, Ont.: PaperJacks, 1980.

Nulman, Stuart. Beyond the Mountain: True Tales about Montreal. Kirkland, Quebec: Callawind Publications, 2002.