bouncy rope, hence the name slack line. these days the line meche walks is more taut, and he takes the sport to new heights. once the nylon rope is stretched and anchored, meche gets to work. he makes it look easy, but, make no mistake, it's not. even for members of meche's entourage, who all use a harness. ♪ >> meche keeps his fear of falling in check. >> fear is not good. if you don't know how to control fear, it's becoming way more dangerous. >> green lake, austria, meche traverses a distance world record, 525-foot 12-minute walk over the icy cold green lake. >> it's really cold.