A Reporoa man who suffered burns to most of his body after his boat exploded into flames at the Gull Petrol station in Paengaroa is in a stable condition.

The 45-year-old man was with friends fuelling up the boat at the service station, on the corner of State Highway 33 and Lemon Road, when the fuel ignited at about 4.30pm on Friday.

The remains of the boat after it caught fire at Gull Paengaroa on Friday. Photo: Supplied.

The man was immediately engulfed in flames on the forecourt and later airlifted to Waikato Hospital by the Trustpower TECT Rescue Helicopter.

He received serious burns to his legs, arms and abdomen.

A Waikato Hospital spokesperson said the man is now in a stable condition in a ward.

Gull general manager Dave Bodger says the nozzle went into the rod holder instead of the fuel tank and following this there was an ignition and an explosion.

The service station was closed for several hours as specialist contractors tries to determine the cause of the incident.

As of yet, the cause of the ignition is yet to be discovered and the investigation is still ongoing, says Dave.

At the time of the incident the boat was towed from the forecourt to a safe area before firefighters extinguished the blaze.

Maketu Fire Brigade responded to control the fire and secured a landing area for the helicopter.