He brought along world-class paragliders Tim Alongi, Jean-Baptiste Chandelier and Cyrille Marck who all helped him get the kayak back up the dunes.
With regard to how risky the runs were, Walter told Red Bull, “I was curious to find out how fast I could go, and you can actually get quite a lot of speed! I think I went around 60 kph [37 mph].”
Source: Inside The Games