Two crew and nine passengers were thrown overboard when waves capsized the boat, leaving painter Geoff McBaron "100-odd" metres from the vessel, trying to save a young man struggling in the rough conditions.

Mr McBaron said he and several others were washed away when 10-metre fishing charter boat Firebird overturned between North Stradbroke and Moreton islands.

He and the other eight passengers on board the Moreton Island Fishing Charters vessel had been treated to a day of fishing on behalf of their paint supplier but were instead battling to stay afloat shortly after 6am.

The Burpengary East 52-year-old said the first wave knocked the boat slightly off course as they were crossing the South Passage Bar, before the second finished the job.

"It was straight up and down and knocked us back and a few blokes got caught underneath," he said.

"A couple of us got sort of washed away. It was pretty hard out there.

"I was stuck out there with a young boy who couldn't swim, about 100-odd metres off the boat.

"It was a struggle. He was screaming and carrying on and really he was fighting me and pulling me down so he wasn't much help, but [we] got back on the boat."

For his efforts, which he admitted may have saved the young man from drowning, Mr McBaron copped cuts to his wrist, chest and foot and had to drop everything but his shirt and "jocks" to stay afloat.

Rodney Kerr, 66, was airlifted to the Princess Alexandra Hospital with a suspected spinal injury while the young man, who Mr McBaron thought was about 18, swallowed a large amount of salt water. A third patient had a big cut to the head, while others were assessed by paramedics at Dunwich on North Stradbroke Island.

After the capsize, everyone had made it back to the boat capsized on the bar but Mr McBaron said waves continued to push people off, with others scrambling to get them back on board as they waited for help.

"It was looking like we'd lose a couple there," he said.

"It was looking pretty bad. I was so happy to see the police rescue and choppers and that."

Water police were the first to reach the stricken vessel, with one officer diving into the choppy water to help drag people to safety.

Bayside Patrol Group Acting Inspector Steve Hollands said the situation had the potential for "dire consequences".

"My understanding was the actions of the officer was very brave," he said.

"With any maritime situation, there's obviously a delay in getting resources out to them, which heightens the risk so we're very grateful that all persons were able to be saved."

Mr McBaron said the accident was no one's fault, just something nature threw up that couldnt be avoided.

Company owner Mat Hubbard declined to comment until he could make sure everybody on board was ok.

The boat was still being towed back to the mainland on Wednesday afternoon.