By 1755 he was an able seaman in the "HMS Centaur", the next year a midshipman on the "HMS Union" and the "HMS Neptune". These were the flagships of Admiral Charles Knowles. In 1757 Hunter took part in an attack on Rochefort. In 1757 he was involved in the attack on Quebec. Hunter passed his exams in navigation and astronomy in 1760 and qualified to be a lieutenant. It took until 1780 to get a job as lieutenant.