In Chapter Six of Theodore Taylor's The Cay, Timothy and Phillip decide to abandon their raft to beach on a deserted island because Timothy was eager to get off of the ocean and felt sure they would be able to find better provisions and a way to get help on the island.
Phillip protests against abandoning the raft, arguing that his father had the navy out looking for them, but Timothy insists. Once Timothy pulls the raft onto the island's shore, which he describes as a "beautiful cay," he notes that the waters are full of fish and Langosta, which is native Caribbean lobster. Timothy knows they'll be able to roast those for their meals. Timothy goes off to explore the island and decides they are probably on a cay called Devil's Mouth that is surrounded by sharp coral reefs. While ships can't reach the cay, Timothy is still certain they have a greater chance of being rescued on the cay because they can build a bonfire, and planes flying overhead will be able to see the signal smoke much more easily than they could see the smoke from Timothy's torch on the raft in the ocean. Hence, all in all, Timothy insisted that they abandon their raft for the cay because he was sure they would be better off and more likely to be spotted and rescued.