[2][3][4] Patey served as a midshipman aboard HMS Shah as part of the British Pacific Squadron under Admiral de Horsey during the Battle of Pacocha, an action in company with the corvette HMS Amethyst on 29 May 1877 with the Peruvian armoured turret ship Huáscar which had been taken over by rebels opposed to the Peruvian Government and, it was feared, could be used to attack British shipping.

He was promoted to sub-lieutenant on 21 March 1878, and while upon the voyage home HMS Shah was diverted to South Africa to assist in the Anglo-Zulu War.

Patey served in the naval brigade which was formed to fight ashore, for which he received the South Africa Medal.

As such he was assistant to the Director, Reginald Custance, who asked Patey to join him when he was appointed second in command of the Mediterranean Fleet in November 1902.

Patey was therefore appointed in command of the battleship HMS Venerable on 12 November 1902, for her first commission after completion, as second flagship on the Mediterranean Station.