Dual investigations have been launched after a log carrier's engine failed at the entrance to Port of Tauranga this morning.
The Singaporean-registered log carrier, Funing-9690913, was bound for China when it lost power at the entrance to the Port of Tauranga about 12.30am.
Without power, it could not steer and drifted to the edge of the channel at the base of Mauao. It is believed to have snagged a marker buoy.
About 20 crew members were on board and there were no reported injuries.
The ship was towed away and is now anchored in deep water outside Tauranga Harbour.
The Funing will not return to port until authorities give permission and its propeller and rudder must be inspected by divers.
The ship's hull is understood to be intact and there was no pollution.
The Transport Accident Investigation Commission and Maritime New Zealand are investigating the incident.
The commission's investigation will focus on the causes and circumstances of the incident and the Maritime NZ investigation will focus on whether the rules were followed correctly.
Maritime New Zealand's deputy director of safety response systems, Nigel Clifford, said the vessel would be able to continue on to China, if it is "safe to sail without repairs".
"If the vessel requires repairs a repair plan will be established by the owners. Authorities would overview any such proposals."
Commission spokesman Simon Pleasants said a team of three investigators left Wellington for Tauranga mid-morning.
He was not sure whether they would board the ship this afternoon as the interviews could take some time and, for safety reasons, they would not want to be disembarking at night.
A Port of Tauranga spokeswoman said the ship was being piloted out of the harbour "as normal" when the engine failure happened.
"A second pilot was transferred on to the vessel several hours after ... to relieve/assist the first pilot." Both pilots had since been taken off the ship.
Tug boats were also requested to help the vessel.
"Our marine teams did an amazing job in keeping the stricken vessel steady and then towing it to safety."
"The wind and swell was challenging for all vessels involved but the conditions eased throughout the morning," she said.
The engine failure delayed the arrival of one container ship and one log ship, but there were no long-term impacts from the incident.
"We frequently deal with shipping delays and changes due to weather and other operational reasons."
There was a 30-knot wind and significant swell when the engine failed.
High tide was at 7.40am.
The Mauao Base Track was closed as a precaution on request from the Harbourmaster but was reopened by midday.