All 100 of the surviving beached whales at Farewell Spit have been successfully refloated during high tide.
The pilot whales, which had survived since a mass stranding at the beach near Golden Bay in Nelson since Thursday night, were refloated about half an hour ago on the high tide.
At the same time another pod of 200 whales were swimming into shore causing volunteers to scramble, according to Department of Conservation Nelson ranger Kath Inwood.
She said 100 of the remaining 300 whale rescue volunteers who had been caring for and keeping the stranded pod alive since Friday morning were now in the water in a human chain to prevent the two pods returning to land.
Inwood said the two pods were "mingling" while the volunteers were in wetsuits in water "up to the necks". There were also three boats in the water monitoring the situation.
She said there was feeling of elation among all the volunteers over the successful refloat however only time would tell if the whales would return to shore when the tide goes out in several hours.
DOC acknowledged the "amazing work" done by whale rescue group Project Jonah and its volunteers. There was no requirement for more volunteers at this point, but a further call would be made if the whales re-stranded, a spokesman said.
The dead whale carcasses would not be moved while any live whales were on the beach. Local iwi representatives Mairangi Reiher and Shane Graham provided a karakia over the dead whales.
More than 400 pilot whales beached there and were found on Friday morning in one of the country's worst ever strandings.
Hundreds of whales have already died in the stranding and their carcasses litter the beach.
Yesterday 100 whales were refloated at high tide, but 50 returned to the beach and restranded themselves.
A hundred whales were found this morning beached on Farewell Spit, but it was not immediately clear whether the whales had re-stranded or if they were different animals.
Whale rescue organisation Project Jonah said the discovery was made when volunteers returned to the beach at first light today.
Department of Conservation spokesman Herb Christophers said DoC was uncertain at this stage whether the 100 whales were the same creatures that were refloated yesterday at high tide.
"There are volunteers heading out to care for the whales on the beach, and keep them comfortable," he said.
"A refloat attempt will be made on the high tide around 11.30am."
Whether it was successful or not would be known by 3pm.
Volunteers were now also dealing with the possibility of sharks in the water.
Officials were warning volunteers about the risks of sharks which attacked the whale carcases last night and fears they will be attracted to large amounts of blood in the water.
There are also concerns about stingrays in the water and fears the surviving whales could suffer blistering in the hot weather conditions today.