After washing up on the shore of the tiny island, he had (thankfully) found the cooler, which had contained two water bottles, a sandwich, and a postage stamp that had been inexplicably wrapped in cellophane. The sandwich was quickly eaten, the cooler became a basket, and the water bottles refilled with rain after funnels had been constructed from wrapped leaves.
But the stamp had sat wedged between the compound leaves of a palm tree for more days than he dared count. So when he had decided to sacrifice one bottle in what was surely a pointless attempt at reaching the outside world, he had wanted to pray. Having given that up a long time ago, though, he stopped himself when about to make the sign of the cross. Caught in apoplexy brought on by not being able to completely abandon the action, he had taken the stamp and placed it on the letter, as if that seal might carry some weight with whatever postman watched over the sea.