Shortly after 11 p.m. Tuesday night, a passenger on board the Carnival Sensation cruise ship reported hearing an argument between a man and woman inside a stateroom -- the man was threatening to jump over the balcony.
"Go ahead," the woman told him.
So he did -- into the pitch black waters of the Atlantic Ocean, about 30 miles off Port St. Lucie. His calls for help were immediately heard by those on board.
The Carnival Sensation abruptly stopped, turned on its spotlights, and threw markers in the water.
Another ship, the Disney Wonder, was nearby and diverted its course to help. (Disney is the parent company of ABC News).
"We saw a spotlight out the front of our ship, and it was just kind of looking in the water," said one man who witnessed the scene. "We were going, probably, really slow -- a couple of knots."
The Disney Wonder launched its own rescue boat into the pitch black sea. It was able to locate the man by asking everyone on board to keep quiet so that they could hear the man's cries.
"For over an hour he was screaming for help," passenger Marie McDonald told The Associated Press. "We were shouting at him to hold on."
John Barwis, the captain of the Wonder, said the man was lucky. "One of the ways he was fortunate was it was such a still night," he told ABC News. "We could actually hear him screaming."
The 34 year-old man was pulled from the water and brought aboard the Disney Wonder to safety.
"He just got up. He was tired, they hauled him up and they bring him inside," one eyewitness said.
The man had been treading water for an hour-and-a-half in the darkness. Both ships came into port early Wednesday morning. The captain of the Wonder met his newest passenger before he disembarked.
"Beaming -- big smile all over his face. I think he obviously regret what had happened," Barwis said.
The man has not been identified, and was taken to the hospital for physical and mental assessment.
One passenger on board the Disney Wonder tweeted the experience as it unfolded.
"A (drunk?) guy fell off a nearby carnival ship. We could hear his screaming from the water. We stopped and dropped a lifeboat overboard," he wrote.
"The captain got onto the PA system and asked everyone to keep quiet so the lifeboat crew could pinpoint the guy from his yelling.
"the life boat crew scooped him up from the water before the Coast Guard helo overflight even reached us.
"guess that disney magic is real."
The Associated Press contributed to this report