Two ships heading towards the Russian fishing vessel Sparta stranded near Antarctica turned back on Sunday for safety reasons, delaying the rescue effort by a day.
The Sparta is stranded in the Ross Sea about 2,000 nautical miles south east of New Zealand, after ice put a 30-centimetre hole in its hull last week.
The Rescue Coordination Centre says a Korean icebreaker was leading the Sparta's sister ship Chiyo Maru No. 3 through ice in the Ross Sea when the decision was made to escort it back out to open sea.
Spokesperson Geoff Lunt says the conditions were too treacherous for the sister ship to get to the Sparta, even by escort, as it was too slow and not capable of moving in sea ice.
The Korean icebreaker, Araon, would then return to the stricken Russian ship, which it was now expected to reach by about 8am on Monday.
Mr Lunt says equipment for repairs, including steel plates and hosing, has been transferred to the Araon.
