 He was appointed Director of Tactical and Weapons Policy Division of the Admiralty Naval Staff from 1962 to 1963.He was promoted to rear admiral on 7 January 1964, appointed Flag Officer, Aircraft Carriers the same year and appointed a Companion of the Order of the Bath in the 1965 Birthday Honours.Janvrin became Deputy Chief of the Naval Staff in 1966 and was promoted to vice admiral on 27 November 1967.