Hugh Downman was born in Plympton, Devon around 1765. His uncle was Dr Hugh Downman, a physician and poet, who obtained for his nephew an offer to serve aboard the 32-gun as a midshipman. Downman took up the offer, joining the ship, which was then under the command of Captain Mitchell Graham, on 10 October 1776. He served aboard "Thetis" for the next two years, leaving the ship in August 1778 and joining . The "Arethusa" was wrecked off Ushant on 19 March 1779 while chasing a French ship, and Downman and the rest of the crew were taken prisoner by the French. Exchanged in January 1780 Downman went on to serve aboard under Captain Samuel Marshall, before moving into the 74-gun in May 1782. "Edgar" at this time was flying the broad pennant of Commodore William Hotham, and in October that year was part of the fleet sent out under Lord Howe to relieve Gibraltar. In the brief encounter with the Spanish fleet that followed on 20 October "Edgar" had six men wounded.