Werner Alfred Waldemar von Janowski,, was a captured German Second World War Nazi spy and the Royal Canadian Mounted Police's first double agent. He is believed to have been a triple agent by some, underscoring the RCMP's inexperience in espionage. Due to power struggles between the Canadian and British intelligence agencies during the Second World War and the RCMP's inexperience, Operation Watchdog was a failure. Janowski provided little significant intelligence to the Allies: no Abwehr agents were arrested and no U-boats were captured, despite his apparent cooperation. Within a year the operation was shut down and Janowski was sent to a prison in Britain.

German submarine U-518 was a Type IXC U-boat of the Nazi Germany's Kriegsmarine during World War II. She saw considerable success from her launch on 11 February 1942 until she was sunk on 22 April 1945. The U-boat was laid down at the Deutsche Werft in Hamburg as yard number 314 on 12 June 1941, and commissioned on 25 April 1942 with Fregattenkapitän Hans-Günther Brachmann in command. He was replaced on 19 August 1942 by Kapitänleutnant Friedrich-Wilhelm Wissmann. She sank nine ships and damaged three more in seven active patrols. U-518 had a crew of 56, and was by then commanded by Oberleutnant zur See Hans-Werner Offermann from 13 January 1944.