"Implacable" spent February and March 1950 training in the Western Mediterranean and Captain H. W. Briggs assumed command on 1 April. She resumed flight training in the Irish Sea and off the western coast of Scotland until she made a port visit to Copenhagen in mid-July. King Frederick IX of Denmark inspected the ship on 18 July and Admiral Vian transferred his flag to "Vanguard" on 11 September. Two days later she was placed in reserve and slowly converted into a training ship by the addition of extra accommodation and classrooms. During this time she was considered for a major reconstruction that would combine her two hangars into a single hangar with a height of and allow her to operate aircraft. In addition her armament would be modernised and the fuel supply for her aircraft would be more than doubled. A similar reconstruction was then in progress for "Victorious", but it proved to be much more expensive than planned and also took more time than had been estimated. Short of both time and money for the project, the Admiralty cancelled the modernisation in June 1952.