I'm not sure it really falls under the banner of "documentary" but Red Bull Media House make a film called "Flight" a few years ago that profiles a group of snowboarders flying around and doing snowboarding. You won't learn anything watching it but it's some of the best film making I've ever watched. It's beautiful.
I saw it when it was first released and agree, it's gorgeous footage. I forgot the name too and only looked it up because you made me curious if it's considered a documentary or some other classification. The wiki lists it as a documentary.
