The sinking of the whaleship Essex by an enraged spermwhale in the Pacific in November 1820 set in motion one of the most dramatic sea stories of all time: the twenty sailors who survived the wreck took to three small boats (one of which was again attacked by a whale) and only eight of them survived their subsequent 90-day ordeal, after resorting to cannibalising their mates.

Three months after the Essex was broken up, the whaleship Dauphin, cruising off the coast of South America, spotted a small boat in the open ocean. As they pulled alongside they saw piles of bones in the bottom of the boat, at least two skeletons’ worth, with two survivors - almost skeletons themselves - sucking the marrow from the bones of their dead ship-mates.