A boat's on fire in the entrance to Marsden Point Marina in Whangarei.

Northern Fire Communications shift manager Megan Hururu said people were removed from the boat earlier.

A Marsden Point Refinery rescue boat with firefighters on board has been trying to extinguish the fire.

"It appears extra resources were needed, pumps and hoses. The tug boat from the local port has gone out there to assist," Ms Huru said.

Refining NZ spokesman Greg McNeill said there were reports of a man in the water but upon their arrival he'd been rescued by a passerby.

It's believed the fire began in the engine of a 40 foot vessel.