"The time I had spent on my feet had caused them to swell from all the blood rushing to them and they had been so wet I had the onset of trench foot."
He had to walk to Kinlochbervie to catch a bus back to Edinburgh.
The last leg of his hike was so remote that there were no paths.
"The terrain up there was pretty terrible. It was the worst stuff, rolling pathless bogs," he said.
"I didn't know if my feet could take it but I knew I had to get to the town where the bus stop was."
Girvan completed the hike in September last year, an idea he came up with during the first lockdown. He recorded his expedition and later edited this into
a 20-minute film which has now won the best solo film award at the New Zealand Mountain Festival.