How does the author get Rainsford on the island? Is this plausible? Explain.

Richard Connell has his protagonist, Rainsford, fall off his yacht while trying to catch his pipe that he dropped. He falls into the ocean and swims to the island. This isn't a very plausible scenario for such an experienced seaman and adventurer. Still, this is an escape type of story so the suspension of disbelief is warranted.