sharp VL-NZ80 weatherproof bag

I am an avid wakeboarder and so far all my video footage has been from the boat. What I would like to do is shoot video from a large inflatable tube being towed from behind the boat, this means i would be about 1m away from the rider and would get footage from the same angle as i have seen in professional wakeboard films. As the tube is going to by really big and i trust the boat driver the viewcam doesnt need to be able to go under water (as in diving)but it does need to be in some sort of waterproof weatherproof bag. So my question is does anyone know of such a thing and where can i get one from for a sharp digital viewcam VL-NZ80.
Any help please