It was whilst swimming alone in Havana harbour, Cuba in 1749 that Watson was attacked by a shark. He was fourteen at the time. The shark attacked twice before he was rescued.**
Watson was the only son of John Watson and Sarah Watson (née Schoefield). Born in Plymouth, Devon in 1735, he was orphaned in 1741 and was subsequently sent to live with his aunt and uncle in Boston, Massachusetts. His uncle was a merchant who traded in the West Indies. Watson had 'before the age of fourteen years manifested a strong predilection for the sea' and so his uncle sent him to sea as a crew member on one of his merchant ships.
It was whilst swimming alone in Havana harbour, Cuba in 1749 that Watson was attacked by a shark. He was fourteen at the time. The shark attacked twice before he was rescued. The first time, the shark removed flesh from below the calf of Watson's right leg; the second time, it bit off his right foot at the ankle. Watson was finally rescued by his fellow shipmates, but his leg could not be saved and it was amputated below the knee. Watson recuperated in a Cuban hospital and recovered within three months.
Watson married Helen Campbell in 1760. Her father was Colin Campbell, a goldsmith working in Edinburgh. The Watsons had no children. Watson was made a baronet on 5 December 1803. Surely a man with a sense of humour, Watson's coat of arms was designed to reference his ordeal with the shark. Underneath Neptune brandishing his trident, the shield bears Watson's severed right leg, with the Latin motto Scuto Divino ('Under God's Protection') below. In return for his services in America, parliament voted Watson's wife an annuity of £500 for life. Watson died in 1807. His baronetcy descended, by special remainder, to his grand-nephew William.