A Westland Mineral Sands barge has run aground near Westport overnight.
The Manahau came ashore at Carters Beach during a thunderstorm about midnight.
Buller District Mayor Jamie Cleine said the motorised barge was carting mineral sands and had been awaiting suitable weather to come into port.
"It's been anchored off Westport for the best part of a week ... and obviously last night's pretty severe thunderstorms and weather - something's happened and changed for them, and it's ended up coming ashore."
Cleine said Westland Mineral Sands would want to pull the boat back out into the water as soon as possible.
The job would require tugs, but there were none anywhere close to Westport, so they would need to be brought from elsewhere.
Union raises concerns about international crew
The Maritime Union national secretary Carl Findlay said concerns had been raised previously by New Zealand seafarers about the foreign crew and flag of the barge.
There had been no reports of injuries, which Findlay said was fortunate, as the West Coast was a notoriously treacherous maritime environment.
The 97.53m-long and 3706-GT self-powered Manahau had only just come into service in August, carrying mineral sands out of shallow draught port Westport to Nelson.
The Manahau did not have a New Zealand crew and the flag state was Niue, Findlay said.
"Vessels such as the Manahau operating in New Zealand's unique and challenging maritime environment should be crewed by experienced New Zealand seafarers."
It had been extremely disappointing to see substantial government funding go towards a vessel operating in our waters that was neither New Zealand flagged nor crewed, Findlay said.
"In the last several years, we saw an upsurge in New Zealand-crewed coastal shipping, but this is now going backwards with the loss of coastal shipping services, or in this case, failing to provide jobs for skilled local crews.
"New Zealand needs to build its coastal shipping capacity, and that means New Zealand-owned, operated and crewed ships."
