A pod of more than 60 whales at risk of beaching in the Western Isles are leaving the area and attempting to swim south.
Marine experts said the whales had moved from Loch Carnan, South Uist, but were "hugging" the coastline.
The pod was first spotted on Thursday afternoon and it was feared they could die in a mass stranding.
The Scottish government has sent marine protection vessel Hirta to shadow the pod's movements.
A spokesman said the use of acoustic devices would be avoided.
Weather conditions were poor with high winds, rough seas and moderate visibility due to low cloud and rain.
New Environment and Climate Change Minister Stewart Stevenson was being kept updated.
Dave Jarvis, of British Divers Marine Life Rescue (BDMLR), said: "Medics on the scene at Loch Carnan, South Uist, are reporting that the pod of pilot whales has now moved from the location they were in earlier and appear to be endeavouring to leave and head south, but hugging the coastline."
Mr Jarvis added: "The remainder of the coastline is predominantly rocky with numerous inlets and bays which give a separate set of dangers to the creatures."
Volunteers are keeping watch for the whales around these dangerous areas.
Experts earlier warned that it was possible the whales could move back into the loch at any time.
Inflatable pontoons are available to help float any beached or stranded whales if needed.
About 20 of the whales were spotted with head injuries.
It is thought the injuries may have been caused by the whales' attempts to strand themselves on the rocky foreshore of the sea loch.
Pilot whales normally prefer deep water but come inshore in search of squid, which is their main food source.
Last week a pilot whale died after getting stuck in the Sullom Voe in Shetland.
Sick and injured whales are thought to beach themselves to die.
However, at times, dying whales have been followed to shore by healthy animals.
Conservationists have also suggested the whales may have got lost.
In October a pod of pilot whales were in danger in the same sea loch.
Days later, 33 whales, thought to be the same group, were discovered dead on a beach in County Donegal.
Pilot whales can grow up to about 20ft (6.1m) and are among the most common marine mammals.