Following his father into the navy in 1771, Carnegie served in the American War of Independence on the frigate HMS Beaulieu and the ship of the line HMS Sandwich, being involved in the Battle of Martinique in 1780 under Admiral Rodney.
His good conduct during the engagement was recognised by Rodney, who promoted Carnegie to commander and then aided his rise to Post captain in 1782, whereupon he was given command of the frigate HMS Enterprise.

Ten years later at the outbreak of the French Revolutionary War, on 22 January 1792, Carnegie had acceded to the earldom and became the Earl of Northesk.
He was given a new ship of the line HMS Monmouth to command in 1796 and having as his first lieutenant Charles Bullen, the start of an excellent professional partnership and close personal friendship.
 The following year he was caught up in the Nore mutiny but was released by the mutineers to take their demands to London.
 Like many in the fleet, Northesk had some sympathy with the initial stages of the mutiny, and so when the demands were refused, he resigned his position as untenable following his failure to restore order on his ship or gain concessions from the government.

Reinstated by the Admiralty in 1803 with full seniority as a rear-admiral, Northesk was given the 100 gun first rate HMS Britannia as his flagship, and after a brief period in the Channel Fleet, was sent south with Sir Robert Calder to join the blockading squadrons off Spain.
 With him went Captain Bullen.
 He missed the Calder's action in 1805, and joined Nelson's fleet off Cadiz that same year.
Following his father into the navy in 1771, Carnegie served in the American War of Independence on the frigate HMS Beaulieu and the ship of the line HMS Sandwich, being involved in the Battle of Martinique in 1780 under Admiral Rodney. His good conduct during the engagement was recognised by Rodney, who promoted Carnegie to commander and then aided his rise to Post captain in 1782, whereupon he was given command of the frigate HMS Enterprise.
Ten years later at the outbreak of the French Revolutionary War, on 22 January 1792, Carnegie had acceded to the earldom and became the Earl of Northesk. He was given a new ship of the line HMS Monmouth to command in 1796 and having as his first lieutenant Charles Bullen, the start of an excellent professional partnership and close personal friendship.  The following year he was caught up in the Nore mutiny but was released by the mutineers to take their demands to London.  Like many in the fleet, Northesk had some sympathy with the initial stages of the mutiny, and so when the demands were refused, he resigned his position as untenable following his failure to restore order on his ship or gain concessions from the government.
Reinstated by the Admiralty in 1803 with full seniority as a rear-admiral, Northesk was given the 100 gun first rate HMS Britannia as his flagship, and after a brief period in the Channel Fleet, was sent south with Sir Robert Calder to join the blockading squadrons off Spain.  With him went Captain Bullen.  He missed the Calder's action in 1805, and joined Nelson's fleet off Cadiz that same year.
William Carnegie, 7th Earl of Northesk