Authorities are still investigating the cause of the incident and will attempt to salvage the boat on Wednesday.

Authorities say they were concerned about the seaworthiness of a vessel that left port in Ballina early on Monday and broke apart less than 24 hours later off Kingscliff in northern NSW.

Police received a call for assistance from the skipper of the vessel just after 10pm on Monday, after he had made his way to shore and borrowed a phone.

Kingscliff Hotel patron Natalie Evans was in the pub when she saw the man leaving the men's bathroom carrying a shopping bag and an oar.

"He was soaking wet and he had seaweed all over him," Ms Evans said.

"He looked a bit upset, and when I found out why he was there, I felt bad for him really."

Ballina Marine Rescue unit commander Peter Hill said he was on duty when the vessel left the Richmond River at Ballina at 7.30am and travelled out to sea in a northerly direction.

"I took particular note of it because it was unusual and it didn't seem particularly seaworthy," Mr Hill said.

Mr Hill said the boat was 10 to 12 metres long with a single outboard motor controlled by a tiller.

"If weather and wave conditions were good, it could have been okay," he said.

"The gentleman was pretty confident in his abilities and he's the skipper, so the choice to go to sea is up to him."

The ABC understands the boat had been moored at Ballina for the past few months, and had undergone repairs on the slipway earlier this year.

NSW Maritime operations manager Rod McDonagh said the authority had spoken with the owner of the vessel about its condition and his travel intentions.

He said no formal action had been taken by the authority in terms of its seaworthiness.

"There are a lot of notifications and processes before it would get to that stage."

He said NSW Maritime was still investigating the circumstances around what caused the boat to break up and run aground.

He said the outcome would determine whether the skipper would face any further action.

"What happened is still quite unclear; whether he hit rocks or the breakwall is still unknown at this point."

Kingscliff resident Sara Sprake said debris from the boat was littering the beach at Kingscliff when she stepped out for a walk at dawn on Tuesday.

Ms Sprake said she found everything from a shoe and a door to marine flares, which she and a friend picked up to dispose of safely.

She said she was concerned some of the debris might remain on the beach.

"There is a lot that is buried deep. I tried to pick up a corrugated hose, but it was attached to something buried under the sand."

Mr McDonagh said NSW Maritime would be bringing machinery onto the beach on Wednesday in an attempt to salvage the vessel.

He said the beach between the breakwall and the Kingscliff Surf Club would remain closed until the clean-up and salvage operation had been completed.

NSW Health said the man, believed to be in his 40s, remained in a stable condition in Tweed Valley Hospital with minor injuries.

He declined to be interviewed by the ABC.

'Covered in seaweed', shipwrecked skipper swims to pub to call for help