After being trapped in ice since Wednesday, a damaged fishing vessel is now being towed to open water by the US Coast Guard icebreaker, Polar Star.
The 207-foot Antarctic Chieftain called for help on Wednesday after becoming trapped and damaging three of the four blades on its propellor when trying to break through ice floes up to three metres thick in the Amundsen Sea.
On board are 26 crew, half of whom are New Zealanders.
This morning, the Polar Star arrived at the scene where it deployed a remotely operated vehicle to better inspect the damage to the fishing vessel's propellor.
The crew of the icebreaker said they encountered snowy conditions as well as large icebergs along the 690 kilometre voyage to reach the stranded vessel.
"The ice conditions were found to be much more formidable than expected. We are on scene and progressing well with the rescue," said Captain Matthew Walker, the commanding officer of the Polar Star.
Previously, the US Coast Guard said the vessel would only be towed if its propulsion was "inoperable".
Another fishing boat, Janas, which is operated by Talley's, is expected to reach the area on Monday night.
The general manager of Talley's fishing division, Tony Hazlett, said they were heading to the area to see if they could be of assistance.
"It's the law of the sea," Mr Hazlett said. "You get a call and you go and help."
Janas was around 1000 km away around midday.
He said if they did need to tow the damaged vessel, the pair would probably travel around 4 - 5 knots (7 - 9 km/h) in good conditions.
And if the two boats were able to maintain that speed for the 3,900 km voyage back to Dunedin, it would take about 550 hours, or nearly 23 days non-stop.
The Antarctic Chieftain is licensed to harvest Patagonian toothfish in the Southern Ocean.
A spokesperson for Australian Longline Limited, Malcolm McNeil, said the vessel had a moderate haul of toothfish on board and was crewed by New Zealanders because of their expertise.
Mr McNeil said the boat would offload its catch in Nelson.
The vessel sails under an Australian flag and is owned and operated by Australian Longline, which is half owned by Sealord.