He was commissioned lieutenant on 13 December 1760, and promoted commander of the sloop Martin 14 in the Leeward Islands on 1 April 1765, paying her off in April 1767. In October 1770 he recommissioned the Merlin 18, going out to Jamaica from Spithead in June 1771 and paying her off in March 1772
Fotheringham was posted captain of the Garland 24 on 9 October 1773, paying her off in the following July.
In October 1775 he commissioned the new Fox 28, going out to Newfoundland in March 1776. His undermanned command was captured by the American ships Hancock 34 and Boston 24 on 7 June 1777, but he was aboard the Hancock when she in turn was taken on 8 July, as was the Fox, by the Rainbow 44 and Flora 32. At his subsequent court martial in England into the loss of the Fox he was honourably acquitted.
He commissioned the new Resource 28 in July 1778, going out to Jamaica that winter, and retaining her until the beginning of 1781. His final command was the Ruby 64, which he commanded briefly that year with the flag of Vice-Admiral Sir Peter Parker at Jamaica.
He died in 1784.
During 1773 he took up residence at 15 Orange Street, London