Campbell said he was the last passenger to go out on one of the rafts, and grabbed Sullenberger's arm on the way out to say thank you.
"He very humbly just said to me, "You're welcome,'" Campbell said.
The hearing also examined the dangers posed by bird strikes. Sullenberger landed on the Hudson Jan. 15 after the plane struck Canada geese upon taking off from New York's LaGuardia airport.
"There were many birds," Sullenberger said today. "They were very large, and they filled the entire windscreen."
The transportation board previously said it found no problems with either engine up to the point when the bird strikes were reported.
In late April, travelers were able to get their first glimpse of federal data documenting where and how often planes hit birds when the Federal Aviation Administration made public its bird strike data for the first time.
Many travelers had argued they had a right to know where and when bird strikes happen after the emergency landing of US Airways flight 1549.
The database includes reports of fewer than 3,000 bird strikes per year for the first several years of reporting from 1990 through 1994. The numbers increase from there, hitting a peak of 9,650 bird strikes in 2007. In total, FAA data indicates there have been more than 73,000 bird strikes in the United States in the past eight years.
Still, Sullenberger said warnings they get about birds aren't always helpful.
"In my experience, the warnings we get are general in nature and not specific and therefore have limited usefulness," he testified.
Sullenberger also told NTSB members he has about 20,000 hours of flying time -- and said that experience paid off. His comments came on the same day that concerns about pilot training and experience prompted the FAA to begin immediately focusing on regional airlines' training programs to make sure they're up to par.
"I think that [experience] allowed me to focus clearly on the highest priorities at every stage of the flight without having to constantly refer to written guidance," Sullenberger said.
"No matter how much technology is available, an airplane is still just ultimately an airplane," he later added. "The physics are the same and basic skills may ultimately be required when either the automation fails or it's no longer appropriate to use it."
In the aftermath of the crash, several survivors told their stories, recalling that just before the water landing, the pilot told passengers to "brace for impact" and flight attendants shouted out "brace, brace, heads down."
"I chose my words carefully," Sullenberger said today.
As for any regrets, Sullenberger said, "I tend to think I wish I'd had more time to more fully apprise the flight attendants of the situation that we faced."
Still, he credited his flight attendants and passengers for a smooth evacuation once the plane was on the water. Once in the river, the flight crew quickly opened the forward doors to deploy the evacuation slides, which double as life rafts, and passengers scrambled out the front and over-wing exits.
"People were moving quickly, but there did not seem to be any panic," he said. "I think it's largely a result of the flight attendant crew being so professional and by exhibiting an outward, calm, professional demeanor, the passengers responded in kind and behaved very well."