It was a nightmare for a cruise-ship passenger.
No one saw him fall overboard, and he had to tread water to stay alive.
It happened on Royal Caribbean's Oasis of the Seas. INSIDE EDITION got a tour of the massive vessel in 2009. Think of it as putting the Empire State Buildling on it's side and floating it in the ocean.
In the new incident, the ship was off Cozumel in the Gulf of Mexico, when a 22-year-old passenger from Colorado somehow went over the side. Because no one saw him fall into the sea, the cruise ship steamed away.
Incredibly, he managed to stay afloat until a Disney cruise ship came by.
David Hearn was a passenger on the Disney Magic and shot a video of a Disney lifeboat heading out to the rescue.
He explained to INSIDE EDITION, "It was very windy that morning, very choppy, high seas."
INSIDE EIDTION's Megan Alexander asked, "Are you shocked that this man survived?"
"Oh, absolutely. The fact that he'd been treading water for that long is just unbelievable," said Hearn.
The crew wenched up a lifeboat with the rescued passenger on board. The Disney Magic made a loop in the water to rescue the American.
Hearn explained, "We were a few yards further away from him. His screams for help probably would never have been heard. If we had gone the other direction, it could have been really tragic and we may have run him over."
What's it like to fall off a cruise ship?
Sarah Kirby, who acknowledged she had too much to drink, fell overboard on a birthday cruise in the Caribbean in 2012. She told us she hit a lifeboat on the way down, resulting in terrible injuries.
Alexander asked Kirby in 2012, "What was it like seeing the cruise ship sailing off into the distance?"
"Panic. Pure terror," said Kirby.
She had to tread water in the pitch darkness for 90 minutes.
Kirby said, "I felt helpless. Helpless and hopeless. It was pitch black out there. There's no land. There's no lights."
Eventually, her cruise ship realized she was missing and turned back to rescue her.
We can only imagine how lucky this guy feels to have survived.