HMCS Windsor is a long-range hunter-killer (SSK) submarine of the Royal Canadian Navy, the second submarine of the Victoria class. She is named after the city of Windsor, Ontario. Built for the Royal Navy as the Upholder-class submarine HMS Unicorn (pennant number S43) she was purchased by Canada when the United Kingdom decided to move to an all-nuclear power fleet. During the refit for Canadian service, the submarines were equipped with the Lockheed Martin Librascope Submarine fire-control syst