General Zaroff inhabits the mysterious Ship-Trap Island in "The Most Dangerous Game," known by sailors for the dangerous waters that surround it. The island is located somewhere in the Caribbean Sea, through which Rainsford is passing on his way to South America to hunt "up the Amazon" River from "Rio" de Janeiro. When Rainsford swims ashore, he first encounters a rocky beach with cliffs above, and an adjacent jungle. When he awakes the next afternoon, Rainsford follows the shore to what he thinks is a village because of all the bright lights. However, it is a single mansion set on a bluff with cliffs on three sides. When Rainsford meets Zaroff, he introduces himself as being from New York City; Zaroff tells him he is a Russian Cossack. Zaroff eventually shows Rainsford a false-channel off the island from where most of the shipwrecked sailors come.
During the ensuing hunt, Rainsford travels through the dense jungle, finally coming upon an area he calls Death Swamp that was filled with quicksand. Further ahead he sees a gap which leads to the shore, and from across a cove he can see Zaroff's chateau on the hill. From this spot on the edge of the cliff, twenty feet above the waters below, Rainsford makes his plunge to escape Zaroff.
So the body of water surrounding the island is the amazon river?
The most dangerous game.