Only crazy daredevils would see the longest, deepest and largest glacier in Europe and think, "We should totally bodyboard down that thing." That's exactly what Claude-Alain Gailland and Gilles Janin did recently, conquering Aletsch Glacier in Switzerland with a seven-mile hydrospeeding ride down the treacherous ice river.

"This is a very unusual activity — most wouldn't dare to hydrospeed on a course like this," said photographer David Carlier, who documented the duo's run. Just to give some scope into its massive size, the Aletsch Glacier forms at a point where four other glaciers meet. "We are talking about a handful of guys in the world who can do it, as it requires a lot of knowledge and expertise."

So it's all the danger of the skeleton, with all the danger of of falling into a frozen lake, plus all the danger of sledding down an avalanche, with none of the safety of staying at home and watching "Ice Road Truckers." What's not to like!