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...