In the autumn of 1943, one of the most spectacular intelligence duels of World War II unfolded. Four German U-boat commanders were planning an escape from a Canadian POW camp while a submarine was to cross the ocean to bring them back to Germany. Neither side realized the enemy knew all their moves.
Submarine Warfare Aces Behind Barbed Wire
POW Camp No. 30 in Bowmanville, Ontario, wasn’t like a typical detention center. Behind its walls were the elite of the German submarine fleet, including the legendary Otto Kretschmer—the most successful U-boat commander in Kriegsmarine history.
Next to him were Horst Elfe, Hans Ey, and Hans Joachim Knebel-Döberitz, officers with similar combat experience. For Admiral Karl Dönitz, commander of the German submarine force, retrieving these men held significance far beyond symbolism.
Kretschmer was not going to wait passively for the war to end. Using his position as senior officer in the camp, he devised an audacious plan. Encoded letters began making their way across the Atlantic to Kriegsmarine headquarters. They contained elaborate details for a tunnel escape and a proposal for a submarine pickup off the Canadian coast. Dönitz, convinced of the officers’ value, approved the mission, giving it the codename Kiebitz.
For months, the prisoners methodically dug tunnels, working simultaneously on three to confuse the guards if any were found.
Other inmates prepared fake documents, civilian clothes, and maps. The organization operated with military precision, and coded updates regularly informed Berlin of their progress. By August 1943, the main tunnel was almost complete.
A Game of Intelligence and Deception
The Canadian military intelligence intercepted and decoded every letter Kretschmer sent. Instead of preventing the escape, they decided to play their own game. The plan, code-named Operation Pointe Maisonnette, aimed for more than just capturing the fugitives. The Canadians wanted to seize or sink the German submarine intended for the getaway.
Microphones were installed along the tunnels, allowing the guards to track progress in detail. The Germans were allowed to continue digging, all under close observation.
Meanwhile, the British, breaking Enigma codes, passed on intelligence about the rescue mission to the Royal Canadian Navy. A radar station was set up on the coast at Baie des Chaleurs.
A week before the planned escape, luck turned against the Germans. One night, the earth collapsed in one of the barracks, triggering alarm. Kretschmer moved the escape forward by a day, but the next day the main tunnel’s ceiling gave way. The Canadians immediately arrested the four commanders. It seemed the entire operation had failed—but not for everyone.
Lone Escape and Naval Ambush
Wolfgang Heyda, another German officer, had been making parallel escape plans. As camp senior, Kretschmer was aware and approved, also passing information about the incoming submarine. When his comrades were arrested, Heyda managed to slip out of the camp, heading for New Brunswick. His destination: Pointe de Maisonnette beach.
The journey was tense. The Canadian military police stopped him twice. His excellent English and fake documents saved him the first time. The second time, he was recognized, but instead of arrest, he was put under discreet surveillance. The Canadians hoped he would lead them straight to the submarine. When he finally reached the beach, he was arrested and taken for interrogation.
Meanwhile, U-536, under Rolf Schauenburg’s command, traveled thousands of miles from Lorient, France. After surviving a British air attack, the U-boat reached the Gulf of St. Lawrence.
There, a squadron of Canadian warships was waiting. Radar picked up the U-boat as it waited at the rendezvous. Schauenburg managed to dive, enduring hours of depth charge attacks even as some crew passed out from tainted air. The submarine made it to open sea, but its fate was sealed: on November 20, 1943, Canadian and British destroyers sank it off the coast of Portugal.
Autor
Rory Thornfield
Rory's grandfather left behind a wartime diary filled with accounts of a minor Burma skirmish that history books never mentioned. Reading it, Rory realized: behind every famous battle are dozens of forgotten struggles, each with its own human drama.
His preferred topics: The overlooked corners of military history – secondary campaigns, shadow battalions, local conflicts that never made headlines. From medieval sieges to twentieth-century expeditions, he focuses on the soldiers, not the generals. The people who faced impossible choices and carried those experiences forever.
Rory strips away the romanticism without losing respect for those who served. He combines tactical analysis with personal stories, examining human endurance and moral complexity rather than celebrating warfare. His writing is balanced, thoughtful, and deeply researched.
Outside work, Rory visits forgotten battlefields (now quiet farmland), photographs war memorials nobody tends anymore, and interviews veterans' families.