1735-81. Born on 21 August 1735 at Swilly, near Stoke Damarel, Plymouth, he was the second son of William Furneaux and his wife Susanna Willcocks.
His early service in the Seven Years War was off France, Africa and in the West Indies, seeing duty as a midshipman aboard the Marlborough 80, being commissioned lieutenant on 19 October 1759 of the Edinburgh 64, and seeing further service in the Mélampe 34 and the sloop Ferret.
From 1766-8 he was second lieutenant of the Dolphin 24, Captain Samuel Wallis, which vessel sailed around the world in company with the Swallow, Commander Philip Carteret. Because of illness to both Wallis and his lieutenant, Furneaux often found himself commanding the vessel, and to him fell the honour of stepping ashore at Tahiti on 25 June 1767 and claiming the island for King George.
Towards the end 1770 he was serving as third lieutenant of the Trident 64, Captain Broderick Hartwell, and with the Falkland Islands dispute being resolved he joined Captain Wallis once more as second lieutenant of the Torbay 74.
On 28 November 1771 he was appointed commander of the Adventure which sailed on 13 July 1772 with Captain James Cook of the Resolution on his second voyage of exploration. When the two ships became separated on 8 February 1773 Furneaux independently explored the coasts of Van Dieman’s Land. After rejoining Cook in Queen Charlotte Sound, New Zealand, on 18 May 1773 the two parted company again on 22 October, and shortly afterwards Furneaux had the misfortune to lose some members of his crew to a cannibal race in Queen Charlotte’s Sound. He returned home to England on 17 July 1774, bringing with him a Society islander, Omai, who quickly became a favourite of the British establishment, taking residence with Joseph Banks and being introduced to the King. On completing his return voyage Furneaux became the first man to circumnavigate the globe in both directions
On 10 August 1775 he was posted captain of the Syren 28, which he commissioned and took out to North America that winter, and on 28 June 1776 he commanded her in Commodore Sir Peter Parker’s unsuccessful attack on Charleston. During the following year he escorted the trade to Antigua before returning to New York, but his command was wrecked by colonial gunfire from Judith Point, Rhode Island on 6 November 1777, five men being killed and twenty wounded. After being released from imprisonment in the following April Furneaux saw action as a volunteer aboard the Isis 50, Captain John Raynor in operations off Rhode Island in August 1778 when that vessel was attacked by the César 74.
Furneaux was to live for just another three years, dying at Swilly on 19 September 1781 and being buried in the local church. He was unmarried.
He was described as being genteel and agreeable and was regarded as kind and humane by his men. Some commentators described him as a cautious navigator and explorer.