More water pumps will be rushed to the crew of a stricken Russian fishing boat stranded in Antarctica as they battle to stay afloat while waiting for rescue ships to arrive, officials said Tuesday.

The nearest vessels are still several days away and are being hampered from reaching the Russian-flagged Sparta because of thick ice in the frozen Southern Ocean.

The crew have attached mooring lines to the ice to give the ship greater stability and are managing to pump out water at the speed it is coming in, but New Zealand rescue officials said they need more pumps and fuel.

The ship's agents in New Zealand and the United States are getting pumps, fuel and patches together for a New Zealand Air Force Hercules to drop near the Sparta on Wednesday.

The Hercules has already made one mercy dash to the Sparta, dropping off pumping equipment and fuel on Saturday.

"In the meantime, the crew of the Sparta are continuing to pump water from the vessel and so far have managed to keep up with the ingress of water," rescue coordinator Kevin Banaghan said.

"While all the crew are currently safe on board, the vessel still remains in a precarious position and is unable to move until the hole can be properly repaired."

The Sparta, with a crew of 32, sent out a distress call early Friday from near the Antarctic ice shelf, about 2,000 nautical miles southeast of New Zealand, when it was holed by ice and started to list.

Banaghan said three vessels were trying to reach the stranded vessel with the South Korean icebreaker Araon about six days away. The progress of two ships closer to Sparta was being impeded by ice.

"Currently the Norwegian vessel Seljavaer is standing by in a small area of open water as ice conditions are too dangerous for it to continue trying to make its way to the Sparta," he said.

Sparta's sister ship Chiyo Maru No 3 is about 100 nautical miles away "but it is not ice-strengthened and its approach will be slowed as it navigates the ice pack".