Promoted to rear admiral on 7 May 1872, Hay became Second-in-command of the Channel Squadron in January 1875, hoisting his flag in ironclad battleship HMS "Northumberland" and then the ironclad battleship HMS "Black Prince", and then became Commander-in-Chief of the Channel Squadron, hoisting his flag in the armoured frigate HMS "Minotaur", in November 1877. Promoted to vice-admiral on 31 December 1877, he was sent to the Mediterranean in July 1878 to take control of Cyprus and to occupy it in accordance with decisions reached at the Congress of Berlin.