The latest episode in Channel 4's Daredevils series was about Dean Potter, the world's leading exponent of slacklining - the sport of balancing on nylon rope stretched between two anchor points. The emphasis is on the word slack - as in slack, rather than taut - with no pole or safety equipment, and Potter does it thousands of feet above the ground in California's Yosemite Valley. Not surprisingly the photography was breathtaking, and the viewer was given an inkling of the "hyper-aware state" that Potter goes into as he walked along the 100 foot rope.
The key moment in the film was the controversy surrounding his solo climb of Delicate Arch, in Utah, an act that seemed to be the catalyst for the breakdown of his marriage. However, it wasn't totally clear how Potter was responsible for making the rope grooves in the rock, although an article in Outside attempts to explain the issues.