Ferry-goers crossing the River Clyde on Saturday had been treated to a rare sighting of a group of orcas, believed to made up one bull, one calf and four females.
The pod were spotted swimming and jumping in and out of the water, hunting seals.
Pictures and video footage of the pod were posted on social media by people crossing the river on one of the ferries with one stating it was a “once in a lifetime experience”.
Today keen sealife spotters are lined up along the shore, hoping the majestic creatures will return.
David Nairn, from the Clyde Porpoise marine mammal project, said: “There are lots of people from our community sightings group spending the day beside the shore with their binoculars.
“People make a special effort to sight iconic orca and larger whales.
“There were groups of people all along upper Clyde coast yesterday and it is great that magnificent creatures can bring so many people together.”
It is rare for killer whales to be spotted in the Clyde and whale experts said they were looking for seals and porpoises.
Corinne Gordon, from the British Divers Marine Life Rescue, which helps stranded animals in UK waters, said her organisation had spent Saturday monitoring the pod.
She said: “There was a pod of six – one bull, one calf and four females – and about 8.45pm they were heading west towards Greenock, in a deep shipping lane and away from danger. Hunting for seals
“At one point they were heading east and got past Dumbarton and as far as up by Erskine Bridge, following food – shoals of fish and seals. There are plenty of seals in the Clyde at the moment.
“These are a pod that generally reside in Orkney and they’ve come down. It could be the weather or it could be food.
“We had one come into the Clyde couple of years ago. They are not strangers there but it’s not common.
“We are expecting them to go back out to sea and then head north,” she added.
Orcas are sociable animals and travel in groups of up to 50. Despite their “killer” nickname, they have never been known to show aggression to humans in the wild and rarely among themselves.