A 47-year-old has survived a dramatic slide down an icy mountain, and caught it all on camera.

Lifelong climber and safety consultant Mark Roberts was knocked off the side of Mount Snowdon, Wales, by a chunk of falling ice, reported the BMC.

Roberts, who was wearing a helmet-cam, decided to release the clip to help other people learn about safety.

In an interview with BMC, he said the fall happened when a fellow climber above him was trying to get good axe placement.

"I'd already felt some smaller bits come down and was keeping a watch above me," he told BMC.

"Then it happened: A sizeable chunk of solid ice flew straight down towards my head. I had little time to respond."

He said he knew immediately he was going to fall some distance, but all he had time to do was protect his head and neck.

Despite the fast fall, he was just "a little dazed" when he stopped.

"Interestingly, I had the foresight to check the cam was still attached and just hoped the vid had recorded that: It wasn't one for repeating," he said.

"Time seemed a little different...I could see movement of someone below and gave them the thumbs up to show I was conscious and not too badly injured."

Roberts said if he were to go out on the course again, he would have talked about the route more with his partner.

- © Fairfax NZ News