 On one occasion during exercises with an error resulted in a practice torpedo becoming embedded in the submarine's casing.Following an 18-month refit at Devonport Dockyard she commissioned for the third time on 3 December 1969.In 1970 she was present at Portsmouth Navy Days "Walrus" also attended the 1977 Silver Jubilee Fleet Review off Spithead when she was part of the Submarine Flotilla.