Although we might imagine that it would be safer working for the Merchant Navy than for the Canadian Navy, it was actually more dangerous. German U‑boats, used in both wars, were a formidable force; they torpedoed and sank more than 60 merchant ships. Naval mines, camouflaged in the waves or under the water, also posed a huge risk.

The fact that merchant ships were quite slow and rarely had military capabilities made them easy targets for U‑boats. Unfortunately, the death toll of merchant seamen during the Second World War was high. Of the 12,000 sailors, more than 12% were killed, compared to 2% of the 100,000 who served in the Navy.

To limit the danger, in addition to the convoys, other measures were put in place. Some ships installed defensive weapons, but only military personnel were able to operate them. A less common solution was to fit them out so that they could be accompanied by an air escort.