A third attempt to rescue a ship stranded off East Antarctica since Tuesday has failed because of fierce winds and poor visibility.
An Australian icebreaker trying to reach the Russian scientific mission ship was forced to turn back.
Earlier attempts by Chinese and French icebreakers to reach the Russian ship Akademik Shokalskiy were also foiled by the thick ice.
The Shokalskiy is stocked with food and is in no danger, its team says.
Seventy-four scientists, tourists and crew are on the ship.
'Snow showers'
The vessel is being used by the Australasian Antarctic Expedition to follow the route explorer Douglas Mawson travelled a century ago.
The BBC's Andrew Luck-Baker, on the Shokalskiy, said scientists on board thought the ice was much thicker than usual for this time of year.
The Aurora Australis icebreaker had been forced to turn back to clear water and was repositioning to try to find another route towards the Shokalskiy, he said.
"[The icebreaker] was slowly, slowly, trying to carve a path to us," he said. "It stopped for some time, and [now] has actually gone back the way it came. And it's now in clear water.