Dr John Howe of the Scottish Association for Marine Science (SAMS) will feature in a Christmas special of the BBC's The Adventure Show with television presenter and outdoors expert Cameron McNeish.
Dr Howe, a marine geologist, explained how the unusual rock formations around Clach Thoull, in Port Appin, were formed as he and Mr McNeish walked round the picturesque route.
The programme will make up part of The Adventure Show special which sees Mr McNeish travel north from Lorn to Ullapool in his own camper van, learning about the landscape and trying out various activities on the way.
The celebrity hiker said: "With this programme I am trying to visit areas off the beaten track. I have never been to Port Appin before – it is a beautiful place – but I do know the Oban and Lorn area quite well from my time as a sea kayak instructor on Loch Creran."
Dr Howe, who lives in North Connel, is head of Biogeochemistry and Earth Sciences at SAMS, near Oban. He said:
"It was great to meet Cameron. We had a good chat and experienced real Argyll weather, from sunshine to hail in a matter of minutes.
"Port Appin is known for its quartzites and that area around Clach Thoull is around 700 million years old.
"Of particular interest to geologists are the ancient rocks on the shallow water seabed and the iconic arch that represents the higher sea level around 7,000 to 12,000 years ago."
People can join Dr Howe on a trip to Kerrera as part of the Festival of the Sea from 10am – 4pm on Friday, May 29 when he will showcase Kerrera's geological evolution during a walk to Gylen Castle.