AMESBURY - By the time the Essex left Nantucket on its final and most famous voyage in the summer of 1819, it was no longer the newly built merchant ship that sailed from Amesbury.

After 20 years at sea, it was well past its prime. As was common for well-used ships of the day, the merchant ship had been sold and converted to a whaling vessel, the grimiest and most foul-smelling kind of ship afloat.

Whaler crews hunted sperm whales in small boats and lashed the corpses to the side of the ship for butchering before spending weeks at a time boiling the rendered blubber into the candlewax and lamp and wood oil that drove much of the early 19th-century economy.

The Essex nearly capsized in a sudden storm just two days after leaving Nantucket, an event the crew took as an ominous portent. But aside from a difficult five-week passage around Cape Horn at the beginning of 1820, the voyage to the Pacific whaling grounds passed uneventfully.

In November of that year the flip of a hunted whale's tail destroyed one of the ship's four whaleboats, though this was not unusual. In fact, another of the whaleboats was damaged in similar circumstances just four days later. But as the first mate set about repairing the boat back on the deck of the Essex, the unprecedented happened.

An enormous, 80-ton sperm whale rammed the Essex on its port side, then dove beneath it, knocking off the ship's false keel. In the annals of whaling, a direct attack on a ship by a whale was unheard of, but this unusually large whale shook off the effect of its first impact and circled around to ram the Essex again. This blow knocked the ship backward and broke its hull below the waterline. Within 10 minutes, the Essex was sinking, and the crew had abandoned it in the three remaining whaleboats.

For the benighted score of sailors fleeing the wreck, though, the ordeal was just beginning. Fearful of the supposed cannibalism of Pacific Islanders to their west, the crew elected instead to sail south and east, charting a course of several thousand miles to the South American coast.

A month later, the three boats landed on a small island, but it quickly became clear that the island was incapable of supporting them, and they set sail again. In January 1821, still at sea, the three boats were separated from each other. One was never found. The other two were picked up by separate ships in the second half of February.

Adding irony to horror, while the crew had avoided cannibalism at the hands of native islanders, in their hunger before being rescued, they perpetrated it themselves. In their bid to live as their rations ran out, the survivors devoured seven of their own.

The story of the Essex and her doomed crew quickly became one of the most famous sea sagas of all time, helped by published accounts of several surviving members of the crew. Herman Melville used the story as inspiration for the climactic scene of "Moby Dick," in which the Pequod is destroyed by a giant, vengeful whale. While working as a whaler in the Pacific, Melville met the son of one of the survivors of the Essex, who lent him his father's account of the wreck and its aftemath.

"The reading of this wondrous story upon the landless sea," Melville said later, "and so close to the very latitude of the shipwreck, had a surprising effect on me."

When maritime historian Nathaniel Philbrick published a new account of the tragedy, "In the Heart of the Sea," in 2000, a whole new generation of readers was introduced to the story.