The Real Moby Dick

On August 12, 1819, the whaleship Essex departed Nantucket Island with a crew of twenty men bound for the Pacific Ocean on what was expected to be a routine two-and-a-half-year whaling voyage. Just over a year later, on November 20, 1820, roughly 2,000 miles west of South America, an 85-foot bull sperm whale rammed the ship twice with what first mate Owen Chase described as deliberate malice, sinking her in minutes.

The twenty crew members escaped in three small whaleboats with limited provisions and faced an impossible decision about where to sail. Fearing reports of cannibalism in the nearby Marquesas Islands, they chose...