Hundreds of Farewell Spit residents and tourists have joined conservation workers in a frantic battle to help 123 stranded whales, and more rescue attempts are planned today.

The pod of pilot whales began beaching themselves at Puponga at midday yesterday and by last night were strewn the length of the beach, at the top of the South Island, the Conservation Department's Golden Bay area manager, John Mason, said.

Three had died by early last night. "They have basically thrashed themselves to death," Mr Mason said.

Everything possible was being done to keep the others alive. "We've got sheets and blankets over them and we're keeping them damp. We've also set up sprinkler systems with pumps so we're getting water on to them that way."

Rescuers from Project Jonah and Marine Watch are expected to help DOC staff and locals to refloat the pod at high tide about 2pm today.

Farewell Gardens Holiday Park manager Shelagh Schaab said hordes of tourists were also helping. "There are about three times as many people as whales. They are using their own shovels and spades."

The volunteers were asked to leave the beach last night. DOC marine specialist Andrew Baxter said it was too dangerous to try to refloat the whales in the dark at high tide this morning. "People's safety is our first priority."

Mr Mason said it was likely that only about a third of the whales would be able to get themselves afloat unaided overnight. While some were close to the high-tide mark, others further up the beach would probably need help.

Mr Baxter said strandings were common between November and February, but this was the region's first since 1998.