On November 20th 1820, the whaleship Essex was attacked and sunk by a sperm whale in the south Pacific. The incident inspired Herman Melville to write Moby Dick.
Essex was an 87 foot long, three masted whaler out of Nantuckett. She embarked in 1819 on a planned 2.5 year voyage to the south Pacific whaling grounds under the command of 27 year old Captain George Pollard with a crew of twenty. Arriving on station, she joined the other American whaling ships in harvesting sperm whales from the great southern ocean.
On the day she went to the bottom, the crew of Essex was engaged in their usual duties of harpooning sperm whales and bringing them alongside to remove the spermaceti and oil from their heads. In the midst of this slaughter, a sperm whale much larger than average -- estimated at 80 feet in length -- appeared and attacked the ship, ramming it twice. Breached below the waterline, the Essex quickly took on water and sank. None of the crew members were killed in the attack, so all 21 set out in the ship's three boats to find shelter. They knew they were roughly 2000 miles west of South America, and they had little in the way of provisions.
They made landfall at Henderson Island, in the Pitcairns made famous by the Bounty mutiny. But in just a few days they exhausted the food and water available on the small island. Eighteen members of the crew elected to get back in the boats and seek better conditions, while three remained behind.
It's hard to say which of these groups made the better decision. Of the 18 who set out in the boats, only 8 survived, having eaten 7 of their companions who perished from exposure along the way. After recovering enough of their wits to sensibly explain what had happened, they told their rescuers of the three who had stayed behind. Those three were found, nearly dead, on April 15th 1821.
You can read more about the Essex
here.