Maritime New Zealand is investigating a collision between the Waiheke Island ferry and a launch with two men on board, who were thrown into the sea.
The Fullers ferry had just left Auckland on its way to Waiheke Island when it collided with the motorboat, at just after 8.45pm on Saturday.
An eyewitness told Radio New Zealand the launch was not using lights.
A ferry passenger who wanted to be known only by her first name, Jilly, said there was a loud bang, then an announcement over the loudspeaker to explain there'd been a collision.
She said the ferry crew used searchlights to look for people from the boat, and called out to them until the men responded.
Fullers chief executive Douglas Hudson praised the crew for quick actions in rescuing the two men, saying they did an outstanding job especially considering it was dark and raining heavily.
He says the ferry is back in operation and all ferry services are operating as normal.
The ambulance service says the two men on the launch were taken to Auckland Hospital with minor injuries.
Maritime New Zealand says it is making preliminary inquires before deciding whether to launch a full-scale investigation.