Quebec Convoy

The St. Lawrence and Gulf convoy cycles of the Second World War, the QS (Quebec to Sydney) and SQ (Sydney to Quebec) series that fed ships into and out of the river toward the ocean assembly ports. They ran through the Battle of the St. Lawrence, the 1942 to 1944 phase when U-boats penetrated the Gulf of St. Lawrence and the river itself, sinking merchant ships and the ferry SS Caribou. The threat forced Canada to close the St. Lawrence to transatlantic shipping in September 1942, diverting traffic to Halifax.