Passengers are having an uncomfortable time as the Interislander Ferry is anchored in Cook Strait after losing power.
Passengers were provided lifejackets.
Harbourmaster Grant Nalder says the ferry lost power near Sinclair Head, approximately one nautical mile offshore. He says a mayday was declared.
Mr Nalder says all efforts are being made to keep everyone on board safe. He says they are looking to see what vessels may be able to assist.
The ferry is currently anchored to give engineers time to restore power.
Mr Nalder says there were 3-metre swells with wind speeds of about 40 knots in the area which will make it very uncomfortable for passengers.
