San Nikunau, a Sanford fishing boat, caught fire near the Viaduct Harbour in Auckland on Tuesday.
Forty people were on board the vessel when the fire broke out in the bow of the boat at about 10.45am.
The Fire Service says the blaze appears to have been caused by the engine. Ten crews were sent to the scene near the Viaduct Events Centre.
Everyone was evacuated and no injuries were reported.