The Department of Conservation says rangers and volunteers have worked hard throughout the day to keep eight whales re-floated off Farewell Spit from re-stranding.
Thirteen pilot whales became stranded on the beach at the top of the South Island about 11am on Tuesday. Five have since died, including three during the night.
About 30 rescuers stayed in the sea until about 8pm on Wednesday encouraging the whales to move out into deeper water.
DoC spokesperson Trish Grant says after the whales were re-floated mid-morning, rescuers formed a human chain to nudge them into deeper water. She says they moved them a long way out from shore, but the whales still remain in the area.
The department's Golden Bay conservation services manager, John Mason, says there are strandings once or twice a year at Farewell Spit and generally half the whales die, so for five out of a pod of 13 to die is not unexpected.
DoC says it will check back on Thursday morning to see if the whales have re-stranded.