Swim, Forrest, swim.

That's what Forrest Nelson did, powering through cold, currents, debris and doubt to become just the second person to successfully cross the Kaiwi Channel while starting out from O'ahu.

Dr. Harry Huffaker is the only other who successfully completed the crossing. He did it in 1972.

Nelson becomes the seventh swimmer to successfully cross the channel, according to the Department of Transportation, which validates such swims.

Nelson, 40, a writer for radio in Los Angeles, covered the roughly 27-mile distance in 16 hours and 36 minutes. An experienced open ocean long-distance swimmer, Nelson started 12:20 a.m. March 15 from Sandy Beach and finished at 4:56 p.m. the same day.

"The experience was wonderful. The Hawaiian Islands are gorgeous," said Nelson, who has crossed the English Channel, which is about 24 miles. "Plus, warmer waters are always pleasant."

When Nelson finally hit Kawakiu Beach on Moloka'i, he said he was giddy.

"The joy of being able to finish, on this empty beach at about 5 in the afternoon. I was laughing because it exceeded all expectations. I was the happiest kid on earth," he said.

Nelson credited his escort team of Aaron Napoleon and Jordan Rapoza on the boat, and world-class paddler Chris Owens, who was in the water from start until about daybreak. Also on the boat were Nelson's parents, Gerald and Doris of Wichita, Kan., and his sister, Sara Stauffer of Kansas City, Kan.

"This wouldn't have happened without an escort team," Nelson said. "Since these (escorts) were O'ahu residents, it was so vital to have them out there.

"Chris Owens was with me all through the night. He was by my side. The boat could not stay close so it was up to Chris to keep me safe and keep me in the right direction."

"It was just amazing to see," said Owens, of Sunset Beach. "I told him I was really honored to paddle next to such a world-class swimmer. To see the grace and determination. I haven't really seen an athlete like that."

It wasn't all smooth sailing for Nelson, who had his doubts before and difficulties during the swim.

Nelson called this "the most difficult" swim. "I knew I was going to swim significantly farther," he said. "I know I can swim 20 miles, but that doesn't get me to Moloka'i."

Days before, Nelson said he looked at this challenge as an "attempt." He said "those lingering doubts turned into simmer doubts" about three hours into the swim.

He was drinking liquid at 30-minute intervals but was getting sick and throwing up.

"I don't know if it was seasickness, too much salt water, the exertion of the surf," he said. By about the six-hour mark, he was feeling better.

"It was amazing how he kept on going," Owens said. "I knew he was going to make it. He was in really good spirits psychologically. Once you're like that, nothing's going to stop you."

"He was like a metronome," said Stauffer, who said her brother maintained at least a 53-stroke-per-minute pace for the last nine hours of the swim.

Man and nature also tried to conspire to stop Nelson.

"We first ran into couple difficult currents," Owens said. "This one current I remember I could hear coming from 100 yards away. It sounded like a big river rapids. All of a sudden we were in it. It was really rough. It started to knock me off my paddleboard."

Later, a line of trash stopped Nelson in his tracks at one point.

"Another thing that was scary ... Forrest got bumped by something," Owens said. "He yelled as soon as it happened. Seconds later, he let out another yell. We thought of the worst-case scenario that a predator got a hold of him. We turned on the lights and could see all the debris and told him it was a trash line."

Nelson said: "The final thing that made me stop was a 5-foot stick. At that point I didn't know where I was."

Nelson decided to swim the channel after befriending Bill Goding, an Ala Moana lifeguard who has won numerous Maui Channel swims.

"Bill is a superior swimmer (to me)," Nelson said. "We met last September and we discussed going tandem."

But Bill said it was too cold for him to "stay in the water for the amount of time required." Nelson, meanwhile, had already purchased his tickets to Hawai'i.

"He did it the tough way, going that direction," Goding said.

Nelson's next challenge will be a swim around Alcatraz in May. He plans to return in September to swim the channel with Goding, this time swimming in the opposite direction.