HMCS Ojibwa at sea in 1965. I heard of a number of stories about Canadian Oberon class boats being mistaken for Soviet Foxtrot class boats by the US Navy and Coast Guard. The visual profile of the two classes are very similar and the Soviet boats always had the red star on the conning tower. Canadian boats have the red Canadian Maple Leaf on the conning tower. So, of course they would cause the US sailors who spotted them to have a heart attack.
The Typhoon-class submarine is a ballistic missile-carrying, nuclear-powered submarine (SSBN) deployed by the Soviet Navy in the 1980s. With a displacement of up to 48,000 tons, the Typhoon is the largest submarine class in the world ever built.