Merchant Navy Commemorative Theme Project Media Profile in Sources Resource Type: Organization During the Second World War, a total of 25,343 merchant ships, with 164,783,921 tons of cargo on-board, sailed from North America to Britain. However, the true cost of the war at sea was in human lives lost in defence of freedom - the Canadian Merchant Navy alone lost one seafarer in eight, out of the 12,000 that faithfully served their country.