It is not yet known when a stranded shipping container rescued off the coast of Farewell Spit will reach Wellington.
The Shiling lost power and steering on Friday north of Farewell Spit - the north west tip of the South Island - and issued a mayday call.
An ocean-going tug, the Skandi Emerald, was sent to assist and reached it late on Friday afternoon.
It was towed to a safe place and anchored at Tasman Bay, where Maritime New Zealand would make assessments for the next move.
By Sunday morning it was still under the control of the towing tug.
The plan now was to tow the Shiling back to the capital, but there was no word yet on when that might happen.
Maritime New Zealand said the 24 crew on board were safe, the ship was sound, and weather conditions in the area were stable.
Maritime NZ incident controller Kenny Crawford said a team was actively monitoring the Shiling.
"The Skandi Emerald is a very capable towage vessel, and its crew are highly experienced in traversing conditions such as what could be experienced in the Cook Strait," Crawford said.
Due to the ship's size and location, the owner's agent had contacted Wellington's CentrePort and was working to confirm a suitable place the vessel could safely anchor or berth.
"While the decisions around passage, anchoring locations and towage are managed by the owners of the Shiling, Maritime NZ has oversight, and is liaising with CentrePort and the Wellington Harbour Master to ensure the process is managed safely," he said.
Wellington harbourmaster Grant Nalder said the agencies involved were still working out the details on how to get the ship to Wellington.
"Maritime New Zealand have got the overview of the incident at the moment, so they need to be satisfied that the move can be done safely.
"We will have our criteria for when it comes into the port and we only really want it coming here when we've got the opportunity to bring it in."
Some of the contact people responsible for the ship were in different time zones, which added to the challenge, Nalder said.
But a risk assessment for how to bring the ship to Wellington safely would be done in the next few days.
Nalder said engine faults were not unusual and typically could be resolved quite quickly.
"Sometimes it might be 10, 15 minutes, sometimes it might be half an hour - they're not frequent, but they're not unheard of.
"This ship unfortunately has had a few more than most, and that's why we're being very cautious with it."
Nalder said last year a smaller cargo ship, La Richardais, broke down off the coast of Raglan.
It was towed to New Plymouth, and then on to Wellington, before being towed overseas.
The MV Shiling also broke down in Wellington Harbour a month ago.