More than 70 passengers were involved in an emergency water rescue this morning after a fire broke out in a ferry engine while it was out on Auckland's Hauraki Gulf.

The Fullers Jet Raider ferry was en route to Auckland from Waiheke when the fire broke out around 11.50am.

An automatic fire-suppression unit was activated, isolating the engine room and flooding it with CO2 to starve the fire of oxygen.

"It was out within seconds," said Fullers spokesperson Izania Downie.


Auckland Coastguard duty officer Melissa Ousey said an emergency call was received at 11.54am from the crew who had dropped anchor near Islington Bay, Rangitoto Island.

Five Coastguard vessels and a police boat were alongside the vessel within minutes to help with the incident.

"The crew worked really well to make sure the fire was out and ensured the safety of the passengers on-board," Ousey said.

Another Fullers passenger ferry, Tiri Kat, was en route to Waiheke and came alongside to support. Passengers were transferred on to Tiri Kat and transported back to Auckland.

Izania Downie said the passengers were in good spirits and those already on-board Tiri Kat were very patient, given the emergency detour.

"Everyone was very happy. We offered refunds of tickets but everyone understood it was an emergency and were completely understanding."

Downie said engine fire was a rare occurrence and the ferry had no history of it.

She said it was unclear how the fire started but both Fullers and Maritime New Zealand would conduct full investigations.