Firefighters have contained a massive blaze on a fishing ship in Timaru Port that left three people hospitalised for smoke inhalation.
The fuel fire broke out on the Dong Won 701 at 9pm on Monday with 10 crews working through the night to bring it under control.
It destroyed the bridge and structures on the ship's upper deck but did not spread beyond the vessel.
Four crews remain at the scene along with two tug boats working to cool the sides of the ship as steam and smoke still fanned out from it, Fire and Emergency New Zealand's Steven Greenyer says.
"It's still not fully extinguished, but it's looking a lot better than it was about four to five hours ago. We're reasonably confident it's not going to escalate," he said.
Nick Donaldson, the acting chief executive of port operator PrimePort, said his team had earlier worked to ensure other vessels were not caught up in the blaze.
But now the fire had been contained in the Dong Won 701, he said the plan was to let it burn out while his team looked to resume shipping operations elsewhere in the port.
Environment Canterbury was also monitoring the scene, senior manager Nick Donaldson said.
"Once the fire is extinguished, Environment Canterbury will work with PrimePort to manage environmental risks associated with the subsequent salvage operation," he said.
"At this time, with the fire is contained within the vessel, there are no immediate environmental risks."
Mr Greenyer says two more crews from Christchurch and a further two from Dunedin were on their way to the fire to relieve the crews that battled it overnight.
"Both paid and volunteer firefighters have been working incredibly hard to get this fire under control, in some pretty trying conditions," he said.
"The weather overnight has been appalling, it's been very wet and cold."
He also said firefighters had been careful not to use too much water on the fire in case they sunk the boat.
Police have cordoned off part of Timaru Port as a precaution.