Three whales have been drawing crowds at the head of the loch for about a week, however animal welfare experts are concerned for their safety.
This species is usually found in the north Atlantic where it can dive to 1400m. The Gareloch is only 40m deep.
An attempt will be made on Friday 1st October by the British Divers Marine Life Rescue group to encourage the animals to leave the area and move to deeper water. Six vessels involved in the exercise.
Photograph by Steve Trulock.