Thirteen whales were stranded near the base of Farewell Spit on the northern tip of the South Island on Tuesday morning.
All but one survived the day thanks to 40 volunteers, many from Project Jonah, who kept the whales cool, wet and shielded from the sun.
DOC and the volunteers managed to float the whales in the high tide on Tuesday night, but the light dimmed before they had a chance to bring the whales together as a pod, Takaka ranger Greg Napp told NZ Newswire.
The whales were spread out over 100 metres, but bringing them together would allow them to communicate and swim out together, he said.
But he remained hopeful the whales, which were floating, would get out to sea.
“They could well swim off tonight and hopefully they will,” he said.
If they stayed near the shore, they were likely to be stranded again, he said.
Mr Napp said the whales had been in various states of distress while stranded.
DOC was alerted to a pod of about 60 whales close to the shore off Taupata Point about 8am on Tuesday.
DOC staff lost sight of the other 50 or so pilot whales in the pod, which were still at sea.
Rangers will look for more stranded whales at first light on Wednesday.
Pilot whales regularly become stranded on Farewell Spit and last Monday 39 were stranded near the base. All died naturally or were euthanised.