Although author Richard Connell never specifically identifies the body of water through which Sanger Rainsford sails in "The Most Dangerous Game," he alludes to it early in the story. As Rainsford and Whitney discuss their voyage and the upcoming hunt, Rainsford comments on the darkness of the night.
"You've good eyes," said Whitney, with a laugh," and I've seen you pick off a moose moving in the brown fall bush at four hundred yards, but even you can't see four miles or so through a moonless Caribbean night."
The "moonless Caribbean night" identifies the body of water as the Caribbean Sea. The two men continue discussing their next hunt, where
"It will be light enough in Rio," promised Whitney. "We should make it in a few days... We should have some good hunting up the Amazon.
From the Caribbean, they will apparently sail along the Atlantic coast on their way to South America and to Rio de Janeiro, after which they plan to hunt along the Amazon River.
Connell's ship-trap island was set it the Caribbean sea.