Geography of the Gulf of St. Lawrence
At the start of hostilities and despite the 60,000 km of coastline and three oceans, Canada did not have a significant maritime presence. With the onset of the Battle of the Atlantic, the St. Lawrence and its Gulf became Canada's maritime front.
The geography of the region is extremely important to consider. The Gulf of St. Lawrence is the world's largest estuary with an area of over 230,000 km2. It is sparsely populated, there are three outlets (choke points): Bell Isle Straits, Cabot Straits and Strait of Canso. Also, because of the fresh water brought by the St. Lawrence River, the waters are of low salinity and this has implications for sonar detection of U-boats.
With the onset of the war, medium and small coastal communities within this geographic region became frontline strategic ports, shipbuilding locations and bases for the growing Royal Canadian Navy. The St. Lawrence is Canada's historic transportation and communication link with North America's heartland. In 1939 this importance heightened and became more critical as the St. Lawrence was now Britain's direct link to the Industrial Heartland made.
The strategic importance of the region was not lost on Germany's Admiral Dönitz and the U-boat operational planners. As a result, this marine region of the Atlantic Ocean became a major operational theatre and saw action through the final days of conflict. Many merchant ships, RCN ships, a civilian ferry and U-boats were lost in these waters.
At the start of WWII, Newfoundland and Labrador was not part of Canada. It was still a British colony. With the outset of hostilities, the region became a unified maritime front with St. John's a key naval base for both the Royal Navy and the Royal Canadian Navy. On November 2, 1942 the Scotia landing pier at Bell Isle was struck by a torpedo from a U-boat that had been attacking Iron Ore ships in Conception Bay.