A helicopter pilot called out to a fatal boating accident in Doubtful Sound in Fiordland says the boaties appear to have misjudged the entrance to the Sounds in the dark and plowed into rocks.
Department of Conservation staff found the six-metre vessel shortly before 9am on Monday. A 33-year-old man was already dead and another man seriously injured.
Chris Green, a helicopter pilot for Southern Lakes Helicopters, says the accident happened sometime between 11pm and midnight.
He says that when he arrived at the scene at 9.45am, the boat had been towed into Blanket Bay by department staff.
Police and Maritime New Zealand are investigating.
The name of the dead man will not be released until next of kin have been notified.