He spent nearly 20 hours alone, treading water in the Gulf of Mexico after falling off a cruise ship and being saved on Thanksgiving. James Michael Grimes spoke about the experience Friday, saying it has taught him to not take life for granted.

“My worst fear is drowning and that was something I did not want to have to face,” Grimes told ABC News’ Good Morning America. “I wanted to see my family again. I was dead set on making it out of there. I was never accepting that this was it, that this was going to be the end of my life.”

The 28-year-old from Lafayette, Alabama, was with 18 relatives on a Carnival cruise to Cozumel, Mexico, when somehow he ended up overboard after a day of fun.

On Nov. 23, he had won an air-guitar contest held on the cruise and remembers telling his sister around 11 p.m. that first night on board that he was going to the bathroom, he said. What happened next remains unclear. He said he doesn’t remember falling or landing in the water.

“When I came to, regained consciousness, I was in the water with no boat in sight,” he said. “I can’t float myself, even when I’m trying to. So there had to be … the Lord was with me while I was out there because something was holding me up the whole time I was passed out.”

At some point, he said he thought he saw the fin of a shark, kicking at something that bumped into his leg.

He later chewed on a stick he found floating in the water that appeared to be bamboo. “It gave some type of flavor in my mouth other than saltwater,” he said.

As time passed and the sun began to set, Grimes said the water started getting colder.

“At that time, I thought, how much longer am I going to have to be out here,” he said. “The fall didn’t kill me and the sea creatures didn’t eat me. I felt like I was meant to get out here.”

Then, he saw the lights of a tanker ship and began swimming towards it.

“That was my final little burst of energy,” Grimes said. “The strength that I had, I used pretty much every bit of it to try to make it.”

He said the Coast Guard circled the tanker two or three times looking for him.

“I’d done taken off my socks and everything and was just waving them around my head, trying to do something where they could see me and when that light finally hit me, somehow I heard `We got him’ and I seen (sic) a guy coming down from a helicopter and … right then I thought man I seen the light.”

Grimes said he remembered telling his rescuer he was naked and he told him that was fine. “He told me to hold on to this life vest and I was just thinking `Thank you, you were like a guardian angel coming down for me,” he said.

It’s been a week since the incident and Grimes said the experience has opened his eyes. While dressing in a pair of pants he planned to wear on the cruise, Grimes said he found a fortune cookie fortune in the pant’s pocket that read “Life’s a beach. Enjoy the waves.”

Though harrowing, Grimes said the experience will not discourage him from taking another cruise.

“I might not get within 10-foot of the rails, but I’d definitely be open to going on another cruise, because I really didn’t get to go on this one,” he said.