He was forced to swim 12 miles back to Gulfport because the wind and fast-moving current carried the boat away.
Rescue teams searched for him, but they did not spot him, so Rayner spent 19 hours in the water before he reached the shore.
"I was scared at times but I just said you got to do it. It's life or death. I said maybe this is it and I put my head under the water just to see what it would be like and I didn't like that feeling," said Rayner.
Rayner reached shore dehydrated and exhausted, but he was not hurt.
Police are considering charging the woman from Connecticut who was on the boat with him.