Historian Charles Spencer is sending divers to the wreck site of the White Ship, which sank 900 years ago with the only heir of King Henry I on board.
The ship plummeted to the depths of the English Channel on November 25, 1120, after hitting the notorious submerged Quillebœuf Rock, off the French coast.
Carrying Henry s heir William Aethling and many other members of the Anglo-Norman nobility, it had only just left the coastal town of Barfleur, in Normandy, and had been bound for Southampton.
Everyone on board - bar one lucky butcher - was killed, leading to a succession crisis and civil war in England.