In October 1707 Admiral Sir Cloudesley Shovell — a tarpaulin hero risen from cabin boy to commander of the fleet — brought twenty-one ships home from the Mediterranean through days of gales and overcast that denied every observation. Position-finding at sea then rested on latitude (measurable) and longitude (guesswork: dead reckoning from speed, time, and compass, with errors compounding daily). The fleet’s sailing masters conferred on 22 October and placed themselves safely west of Ushant, in the mouth of the Channel.
They were some hundred miles out of position — north and east of their reckoning, bearing down in darkness on the Western Rocks of the Isles of Scilly.
The night
That evening the fleet ran onto the rocks. The flagship Association struck the Gilstone and sank, by report, within minutes, with all ~800 men; the Eagle and the Romney followed with virtually all hands; the fireship Firebrand struck and foundered with about half her crew saved. Between 1,400 and 2,000 men died — among the worst disasters in Royal Navy history, at the hands of no enemy but arithmetic.
Shovell’s body came ashore in Porthellick Cove. The legends attached instantly and stuck: the sailor hanged the day before for warning (with mutinous presumption) that the fleet stood into danger; the admiral cast up alive and murdered by a woman for his emerald ring, confessed on her deathbed decades later. Neither survives scrutiny; both survive retelling. Shovell was embalmed and buried in Westminster Abbey under a monument Joseph Addison thought vulgar.
The Longitude Act
The disaster concentrated minds wonderfully on a fact every seaman knew: the world’s greatest navy could not find its longitude. Lobbied by mathematicians and merchants — with the Scilly dead as the standing exhibit — Parliament passed the Longitude Act of 1714, offering rewards up to £20,000 (a fortune) for a practical method of finding longitude at sea to within half a degree, adjudicated by a new Board of Longitude with Newton among its advisers.
The prize summoned every crank in Britain — the satirists’ favourite proposed anchoring signal ships across the Atlantic to fire mortars on the hour — but also the two solutions that worked: the lunar-distance method of the astronomers, and the sea clock of a Yorkshire carpenter named John Harrison, whose forty-year duel with the Board became one of science’s great stubbornness stories. The wrecks themselves were found in 1967-71; the Association’s cannon and coin came up from the Gilstone — salvage, at last, from the error that priced longitude at two thousand lives.