Convoy Sailing

A convoy system was employed in Canadian waters from May 1942. During the Battle of the St. Lawrence, Canadian warships were mandated to escort merchant ships. These ships left the port of Quebec and sailed down-stream on the St. Lawrence unescorted until just off the Coast of Bic Island, close to Rimouski.

Just off the Coast of Bic Island, all merchant ships had to arrange themselves in convoy formation. Ships carrying cargo believed to be the main target of German torpedoes, such as oil tankers, sailed in the centre of the convoy, where they could be best protected. Escorted convoys were obligatory for warships and the only acceptable reason for breaking ranks was in case of a U-boat attack. Convoys sailed towards the east in long zigzags; this threw German torpedoes off course, but did lengthen the journey and use more fuel.

Convoys sailed at the speed of their slowest ship. After a port of call in Rimouski, convoyed ships slowed and their pilot disembarked at the Pointe-au-Père pilot station. From there, in small convoys escorted by warships, they began the perilous journey that would take them past Gaspé, then Cape Breton Island and on to the Atlantic.

These convoys, made up of requisitioned merchant ships, would cross the Atlantic to supply Great-Britain with food, munitions, weapons and petrol, but were also essential along the North American coasts and on the River. Along the coasts and the ocean, they had to ensure that the supply network was as effective and safe as could be. Other convoys were tasked with transporting building materials to the Goose Bay air base, and others with restocking supplies at America’s Arctic air base, which was under construction.
Once at sea, the convoys formed up into a large rectangle made up of short columns 1km apart, with each ship keeping a distance of 350 to 550 meters between its rear and the front of the ship behind. The group also had a commodore, who would be aboard the merchant ship at the front of the central line, and who would supervise the convoy.


Convoy on the St. Lawrence River, 1942
Source: Ian Tate’s Collection

The commander was usually at the front, whereas the convoy’s commodore would be in the front row of one of the central columns. Each convoy had its own code; the letters used refer to the origin and destination of the convoy. Thus, Convoy QS-12 leaving Quebec for Sydney, Nova Scotia, was the 12th convoy to make this trip.

Letters used for convoys that sailed the St. Lawrence during the Battle of the St. Lawrence:

LN: Convoys travelling from Saint-Laurent to Labrador
NL: Convoys travelling from Labrador to Saint-Laurent
QS: Convoys travelling from Quebec to Sydney
SQ: Convoys travelling from Sydney to Quebec

From July 1942, convoys were hit hard by German attacks. After convoys QS-15 and QS-19, the losses suffered to convoy QS-33 represent almost a quarter of all ships lost during the Battle of the St. Lawrence. On September 6 and September 7 alone, German U-boats U-165 and U-517 sunk 5 ships.

Faced with a rising toll on lives and shipping, the Canadian government closed the St. Lawrence to all trans-Atlantic shipping on September 9, 1942, and limited coastal convoys to essential levels. This still left considerable work for the defenders, as 40 per cent of traffic on the Sydney-Quebec corridor supported economically vital coastal shipping. Their task was made all the more difficult by a controversial naval decision to divert 17 desperately-needed corvettes to Operation Torch, the impending invasion of North Africa.

Despite closing the river and gulf to all trans-Atlantic shipping, German submarine U-517 sunk corvette HMCS Charlottetown on September 11, 1942. Four merchant ships were sunk in Quebec during the following days.
[…] the tightening of Canadian defence in the autumn of 1942, in particular the offensive air patrols, made the submarines’ traditional chasing tactics impossible, and thus, the Germans “evacuated” the St. Lawrence at the end of autumn 1942. However, the threat was not entirely eliminated, in 1944, German U-boats sunk two Canadian warships.

For more information on convoy sailing:

KIROUAC, André, « 1942 : Alerte dans le Saint-Laurent », Cap-aux-Diamants, no 74, 2003, p. 44-47.
Full-text PDF:

KIROUAC, André, « Un hommage aux marins d’origine hellénique décédés au cours de la bataille du Saint-Laurent », Magazine Gaspésie, vol. 40, no 2, hiver 2004, p. 2-3.

Organisation d’un convoi,

The Battle of the Atlantic: Materials for Educators,, p. 8-20.