Watch the stunning video of the massive sharks circling a tourist boat in Cornwall
Huge basking sharks have been filmed swimming around in a river in Cornwall.
The stunning creatures were caught on video in the estuary of the River Fal.
The video was taken in Carrick Roads by AK Wildlife Cruises, a boat tour agency which operates out of Mylor Yacht Harbour.
Carrick Roads is the estuary of the River Fal near to Falmouth Harbour - the third-deepest natural harbour in the world.
In the video - which you can watch at the top of this article - a basking shark can be seen swimming past the boat tour group.
They can then be spotted again by their dark fins gliding through the water.
Georgia Bardua, wildlife guide at AK, said: "We were out on a normal cruise and hadn't seen much offshore apart from a few seals and sea birds. The sea was quite big that day.
"But as we were coming back in we spotted the top of black fins near to the entrance."
Georgia said the group of guests on the cruise were ecstatic.
She said: "It was unexpected for all of us but they were really excited. I don't think any of them had seen a basking shark before.
"They were really happy and surprised more than anything.
"It was really nice to end the trip on a high like that."
Basking sharks are the second largest fish in our oceans can grow up to 12 metres long and can weigh up to six tonnes.
But they are gentle giants and only eat plankton - a diet which sees them live to be around 50 years old.