Three investigations have been opened into a boat crash in the Bay of Islands that has left the skipper of the Paihia-Russell ferry in a critical condition.
Police are calling for witnesses to a boat being driven erratically as part of their investigation into the passenger ferry collision.
The Transport Accident Investigation Commission is sending two investigators to talk to witnesses and examine the ferry wreckage. It is also seeking any video or CCTV footage taken in the area.
Maritime NZ is also investigating.
A Russell to Paihia ferry and an eight-metre private vessel collided about 11.40am, with some passengers thrown into the water.
The skipper of the ferry, Bill Elliot, was taken to shore by a passing parasailing boat and later airlifted to Middlemore Hospital in a critical condition.
Police said the ferry skipper was a known boatsman in Russell and his boat was familiar among the locals.
St John said one ambulance, one rapid response unit, and a helicopter responded to the incident
Witnesses said a motorboat had crashed into the side of the Paihia-Russell ferry, causing major damage to the port side of the ferry.
A passenger on the ferry involved in the collision described it as a "massive launch" coming full throttle straight towards the side of ferry before it crashed.
Robyn told Checkpoint the boat hit the side of the ferry at the front, close to where the skipper was. Several people were thrown into the water, she said.
She said the skipper looked badly injured, and she thought he was unconscious.
"My husband ran up and tried to turn the motor off. He couldn't because the whole of a cab was gone. So he turned the throttle down as far as he could, because we were only going five knots anyway... Then he got the fire extinguisher and moved all the wood away... from what hopefully would stop any fire coming on and I rang 111."
She said she saw two 300 horsepower outboard motors on the back of the boat.
"The guy that hit us... He turned his boat around and was going away. I don't know if he was doing something like that on purpose or not. But we were just yelling at him to please go and get the people in the water. He didn't seem like he was going to do that without us asking him to do it," she said.
"Very frightening, very traumatic. We were all screaming kids screaming everywhere. Then we had to wait quite a while for another ferry to come and pick us up."
The ferry was a mess, she said.
"So there was wood everywhere throughout the boat and nails, like when we got off the boat we had to watch where we stood cause there were nails everywhere poking up. The whole of the front where the skipper sat was just gone, just smashed up completely."
Rosie Morrow was on a ferry travelling in the other direction, and said her vessel picked up people from the damaged ferry.
Their boat was passing just after the crash, she said.
"There was a massive hole in the side of the [ferry's] hull and a lot of freaked out passengers, yeah it was quite dramatic."
There were about a dozen people on board when the collision happened and the ferry was badly damaged, she said.
"Basically half of its hull down one side was completely caved in and all the sides of the top were lifting over."
The other boat did not look as badly damaged, she said.
"He actually accompanied our ferry back to Paihia and said that he was taking on quite a lot of water, I think a lot of the damage may have been underneath which you couldn't see."
The motorboat must have been travelling very fast, she said.
"Because I think what happened was they hit it and then went up onto it, kind of onto the ferry a little bit."
As far as she knew there was only a man and his child onboard the other boat, she said.
Both Maritime NZ and police are investigating the incident and the damaged boat has now sunk.
Police are asking anyone who may have witnessed an eight-metre private vessel driving erratically to contact Crime stoppers on 0800 555 111.