Darryn Kimlin pushed off from the Lamington Bridge boat ramp in Maryborough, about 200 kilometres north of Brisbane, at 10am on Saturday.
The fisher, travelling in a five-metre fibreglass half-cab boat named Tamarumma, was expected back about midday yesterday but never returned.
When Kimlin last spoke to his family about 3.50pm on Saturday, he said he was fishing in the Granville river mouth at Beaver Rock.
He was described as Caucasian and about 180 centimetres tall, with a slim build, brown-blonde hair and blue eyes, and was wearing a long-sleeve fishing shirt and board shorts.
“Police and family hold serious concerns for Darryn as his disappearance is out of character,” police said, in a statement.
Anyone with any information about the disappearance should call police.
