In February 1772, Trémigon was promoted to captain, and given command of the 64-gun "Alexandre", in the squadron under Orvilliers. In the night of 23 to 24, "Alexandre" got separated from the fleet, and thus failed to take part in the Battle of Ushant on 27 July 1778. Trémigon was admonished after the subsequent inquiry. The year after, he took part in the Armada of 1779.