you should really consider the Sony RX100 for snowboarding. It has non detachable lens (I think it's too much hassle to have multiple lenses) with decent zoom : from 28mm to 100mm (3.6x) and it's insanely small and powerfull.
Let's not forget about another important thing : Optic and digital image stabilization that really works. Video is smooth as butter. Now it sound like I am some kind of sony rep, but I really love my RX100
I mean, check this video shot entirely on it :