Mankamyer was on Carnival Glory for a cruise to the Bahamas. Early Friday morning, he reportedly jumped 60 feet off a balcony into the Atlantic Ocean.
The Coast Guard finally spotted him 30 miles off Ft. Lauderdale's coast. He had treaded water for eight hours. Mankamyer — an average swimmer, overweight, with a collapsed lung —had mild hypothermia, but was otherwise fine.
"I tapped him on the shoulder and gave him a thumbs up and he said, 'Thank you,' " Petty Officer Vincent Martin of the U.S. Coast Guard told CBS News correspondent Mark Strassmann.
Why he went overboard is unclear. Mankamyer's godson, also on board, says they were fighting. Other passengers told the Coast Guard that Mankamyer was drunk.
"They announced over the loudspeakers there was a man overboard," passenger Karl Kleintop said.
Passengers heard sirens. But no one saw a man in the water. Few people expected a happy ending.
"We're shocked. Everyone was shocked because they told us only three to four hours he would survive in the water," passenger Lucy Delia said.
From 60 feet, falling into water can be like hitting concrete. Mankamyer did it, but he's not talking about it in public.
Lt. Marcus Canady flew the helicopter and Petty Officer Howat Will pulled Mankamyer out of the water. Will jumped into the water from 15 feet up and found Mankamyer in "pretty good shape."
"I asked him if he was OK and he said he was exhausted," Will told The Early Show co-anchor Harry Smith. "Initially I started all the conversations. He was trying — once we got him into the helicopter, obviously he was exhausted and he wanted to go to sleep but I kept asking him questions to try to keep him awake."
Canady then had to steady the helicopter at 15 feet above the water while Mankamyer was hoisted up.
"It's a pretty difficult task but it's a task that the coast guard pilots, we always train for," Canady said. "We have our semiannual meetings that keep us proficient in handling situations like this. Myself and any other Coast Guard aviators would have been able to do the same hoist."