Environmental activists have sailed out to confront a seismic testing ship looking for drilling spots off the east coast.
Statoil and Chevron's Amazon Warrior is 125 metres long and supported by two smaller vessels - New Zealand fishing ship the Ocean Pioneer and Panama-registered Maria G.
"It's been refusing to come into port - it's been very hard to protest against, so we decided to go out to it," Greenpeace spokeswoman Kate Simcock told Newshub.
"We got up to about 500m of them. We were really there to bear witness to this climate crime."
Greenpeace wants the Amazon Warrior gone.
"Sixty thousand people have signed on to an open letter to Statoil and Chevron, the oil companies who have brought this ship here and are exploring for oil - it was a very clear message they needed to cease the operation immediately and leave."
Greenpeace says seismic testing ships blast sound waves into the sea every eight seconds, 24 hours a day, disrupting sealife.
Ms Simcock says the activist crews handed over a petition to the crew of the Amazon Warrior, who gave no response.
"It's been refusing to come into port - it's been very hard to protest against, so we decided to go out to it."
Local iwi also had a presence on the protest vessels, led by Maori captain Raihania Tipoki.
"The burning of fossil fuels is changing our world - we are changing our world. We are calling in Armageddon, and it will be destruction by our own hands," he says.
"If we are to stem climate change, indigenous philosophies about how to fit in with nature and not expect nature to fit in with us must be re-adopted."