JFK was stranded on a desert island during WWII, and eventually rescued thanks to a coconut he had carved a distress message into. He later displayed this coconut in the Oval Office.
In 2011, two men got lost at sea and were adrift of 33 days before washing up on an atoll, where they meet a descendant of a long-lost uncle. The uncle had also gone adrift 50 years earlier.
Bill Broyles, the writer for the movie Castaway, chose to deliberately strand himself for one week on an isolated beach in the Sea of Cortez, to force himself to search for water and food, and obtain his own shelter. During this time, a volleyball washed up on shore.
A man was castaway on an uninhabited island for 4 years and 4 months and survived.