WWII in the Gulf of St. Lawrence

Jeff Green | Nov 08, 2023

One of the lesser publicised battles in the Second World War was the Battle of the St. Lawrence.

It was more of a series of incursions by German U-boats, which is short for the German “Unterseeboot”(under sea boat) or submarines, than an all-out battle, but it persisted. From the spring of 1942 until the end of the war, U-boats interrupted important shipping lines in and around the Gulf of St. Lawrence, damaging and sinking commercial and military vessels, and causing injuries and death to sailors for 2 years. A total of 22 ships were sunk and hundreds of lives were lost.

The first attack took place two months after then Prime Minister of Canada, William Lyon McKenzie King, said, in a speech in the House of Commons, that “within a few months navel submarines may well be found operating within the gulf, and even in the St. Lawrence River.”

King added that the U-boats were capable of operating in the gulf for days or weeks before needing to return to Europe for refueling.

The Canadian navy opened a new base, Fort Ramsay, in the Gaspe Peninsula on May 1st of 1942, to provide protection. But the base had only one small sea vessel and no aircraft at its disposal. Eleven days later, German U-553, sank two ships, the SS Nicoya, a British merchant ship, and another freighter, the SS Leto nearbye. A total of 18 sailors died.

Residents along the Gaspse coast observed the attacks, with ships on fire and explosions that could be heard on shore, and the sight of debris, and bodies, floating ashore. But the government of the day, citing wartime secrecy, forbade media reporting of incidents, so the only news came from local gossip.

All inbound and outbound shipping ceased on the St. Lawrence, and resumed a few days later with increased naval and airborne support.

Seven weeks later, on July 6, 1942, German U-132 sunk 3 vessels in an attack on a 12-vessel convoy that was travelling from Ile du Bic, Quebec to Sydney, Nova Scotia. The U-boat was damaged in the counter attack by a naval ship and air support, but it hid at the bottom of the gulf for 12 hours and then left the gulf for repairs.

In late August, two U-boats were involved in a joint raid, resulting in 10 ships being sunk and two others suffering damage, and the deaths of dozens of sailors.

A “special hunting detachment” from RCAF (Royal Canadian Air Force) squadron 113 in Chatham, New Brunswick, was successful in driving a couple of U-boats out of the gulf with repeated depth charges that caused damage but did not destroy the boats.

At the same time, the St. Lawrence and the gulf were closed to all trans-Atlantic shipping traffic, leaving only coastal vessels to protect. The embargo lasted for over a year.

The attacks continued throughout the fall of 1942. On October 14, a Newfoundland Railway passenger ferry SS Caribou, was torpedoed, resulting in a heavy loss of life. 136 crew members and passengers died, and 101 people were rescued.

The Royal Canadian Navy almost sank a German U-boat 43 on October 21. Six depth charges knocked out the lights, blew the battery circuit breaker and even activated one of the U-boats' torpedoes, in the stern of the boat. But the boat descended to 130 metres below the surface, and snuck out of the river to safety.

On November 2, two iron ore freighters were sunk off the coast of Newfoundland and a third was damaged.

There was also one incident, late in 1942, on November 9, when U-518 surfaced in the Baie de Chaleurs near the town of New Carlisle, Quebec. Werner Janowski, a German agent, left the boat and walked ashore. He checked into a hotel. The owners noticed his European clothes and a matchbook from Belgium. When he headed to the train station, they alerted authorities, and he was detained and eventually admitted to being a spy. According to the Canadian Encyclopedia, attempts were made to turn him into a double agent, but they did not work, and he was turned over to British Intelligence and sent to Britain.

As the US navy began to turn the tide in the larger Battle of the Atlantic, the U-boat fleet was mostly redeployed near the end of 1942, and with German shipbuilding capacity now hampered, the attacks in the gulf diminished greatly in 1943.

In 1943, instead of mounting attacks, U-boats were involved in a couple of attempted prisoner of war escapes.

In one case, the RCMP intercepted a letter addressed to several German officers who were imprisoned at the Camp 30 Prisoner of War (POW) Camp in Bowmanville. The correspondence detailed an escape plan in which the POWs were to tunnel out of the camp and make their way through Eastern Ontario and across Quebec to the northern tip of New Brunswick off the Pointe Du Maisonnette Lighthouse to be retrieved by a U-boat. All of the prisoners were apprehended soon after leaving the tunnel but for one, who made it all the way to Pointe Du Maisonette, likely by train. He made it to the beach by the lighthouse, where he was apprehended.

Knowing that a U-boat would be there to pick up the POW, a task Force (Operation Pointe Maisonnette), led by the HMCS Rimouski, was laying in wait in nearby Caraquet Harbour. They detected U-536 off the shore while the POW was being arrested, and took chase. But the U-boat dove into the sea just as the warships began sending depth charges its way, and escaped the Gulf of St. Lawrence.

By 1944, the RCAF had developed sufficient capacity to keep U-boats out of the gulf, and the shipping lanes were re-opened.

But late in 1944, U-boats upgraded with a new ventilation system that allowed them to operate continuously underwater without surfacing, and carried out some deadly missions. U1223 is credited with seriously damaging the frigate HMCS Magog on October 14, 1944, and U-1228 sank HMCS Shawinigan, off Port aux Basque on November 24, killing all 91 crew members, the worst case of military deaths in Canadian territory during the entire war.

Although the Canadian Military were never able to sink or capture a U-boat off the region throughout the war, in the days following the end of the war in 1945, two U-boats U-889 and U-190 arrived in Shelburne, Nova Scotia, and Bay Bulls, Newfoundland, and surrendered.

(Material for the above was sourced from the Canadian Encyclopedia and Wikipedia.)