Battle of The St. Lawrence - Summer 1942

Summer 1942

On 6 July, U-132 sank three freighters off the Gaspé coast and damaged another on 20 July, each time escaping attack by the Bangor-class minesweeper HMCS Drummondville. There were further German attacks in August, on harbours in Labrador and Newfoundland and on a convoy in the Strait of Belle Isle that damaged the USS Laramie.

In September, three U-boats made a joint raid on the St. Lawrence. U-517 sank nine ships and damaged another in a two week period, escaping attacks by escort vessels each time and sinking the Flower-class corvette HMCS Charlottetown on 11 September. U-165 was less successful in attacking merchant shipping but it sank the armed yacht HMCS Raccoon; U-165 was harassed by RCAF patrol aircraft and completed its operation in the Gulf of St. Lawrence with no further incidents.

The continued attacks caused the St. Lawrence River and Gulf of St. Lawrence to be closed to all trans-Atlantic shipping, allowing only coastal trade. In practice, although this embargo strained the Canadian National Railway (CNR) system to Sydney and Halifax, it simplified the management of Atlantic convoys. The embargo lasted until early 1944.