Promoted to captain – in recognition of his services at Eupatoria – on 27 November 1854 and, having been appointed a Companion of the Order of the Bath on 5 July 1855, Hay was given command of the fifth-rate HMS "Forth" in December 1855. Entering politics, he became Liberal Member of Parliament for Wick in the 1857 general election and served his constituents there until the 1859 general election. Returning to sea, he became Captain of the paddle frigate HMS "Odin" on the East Indies and China Station in September 1859 and took part in the Battle of Taku Forts in August 1860 during the Second Opium War. From 1861 he served as commodore on the East Indies and China Station.