More than 400 whales beached themselves in a mass stranding at the sandspit at the northern end of Golden Bay on Thursday night.
About 300 died but the surviving 100 were successfully refloated at high tide about lunchtime today.
Two groups of previously stranded whales at Farewell Spit in Golden Bay are beached again and the Department of Conservation is urgently calling for more volunteers.
Up to 120 of the 300 pilot whales heading out to sea at high tide earlier today did not make it the 26km alongthe sandspit to safety.
DoC Nelson ranger Kath Inwood said two groups of whales, 70 in one and 50 in the other, were beached about 3km from the original stranding site on Thursday night involving 416 whales.
Of those, 300 died and the rest were successfully refloated today and joined another pod of 200.
DoC senior communications advisor Herb Christophers said they would not be attempting to refloat the whales at the midnight high tide due to health and safety risks. He said they had to be careful no volunteers got hurt.
"Black fish, dark night, a flick of the tail and somebody could go down and nobody would know."
Instead they would be back first thing in the morning to check the status of the whales and attempt to refloat any survivors at midday, Christophers said.
Inwood said local volunteers were now being called on to help care for the mammals until dark, but anyone joining the rescue effort must have a wetsuit.