As the protagonist, Sanger Rainsford of New York City, and his friend Whitney sit on board the ship that is a few days from Rio de Janeiro, they talk of hunting the jaguar. They also converse about the large island off to the right that is "rather a mystery," according to Whitney. Even the old Swedish captain is suspicious of the place that is located on the Caribbean Sea.
As Rainsford watches in the dark on the afterdeck, he hears the report of a gun three times. When he stands on the railing of the boat, he leans too far and falls.
The cry was pinched off short as the blood-warm waters of the Caribbean Sea closed over his head.
Rainsford fights this sea until her reaches a shore, where he passes out from fatigue.