Almost two dozen people were using buckets and cloths to help keep the beached whales wet, while a spotter plane was patrolling the area to see if there were any more whales heading inland toward the bay.
However, other experts said the presence of so many calves and mothers suggested the stranding is linked to seasonal migration.
New Zealand has one of the world's highest incidences in whale beachings, Friday's being the third-largest in the country's history.
Project Jonah says it's winding down its operation.
Volunteers are keeping a close eye on those back in the water, with a risk of them getting into trouble again.
Many volunteers came to help them refloat and swim free.
About 200 whales, which were part of a larger group that beached in New Zealand over the past few days, have managed to refloat themselves and swim back out to sea.
DOC then euthanised 20 of the surviving whales with a rifle, whales which were too ill to be rescued or stay alive.
This picture taken on February 11, 2017 shows a volunteer caring for a pilot whale during a mass stranding at Farewell Spit.
"There were about 200 whales in numerous pods just swimming around at risk of stranding", he said.
There have been reports the whales may "explode" on the beach. Volunteers successfully refloated the 17 that were still stranded the next day.
The strandings preceded and followed a strong 5.2 magnitude natural disaster near Culverden yesterday, however Auckland University Marine Biologist Dr Rochelle Constantine isn't convinced that quakes are a significant factor in whale strandings. Sometimes described as a whale trap, the spit's long coastline and gently sloping beaches seem to make it hard for whales to navigate away from once they get close.