During my trip to Glenwood Canyon a month ago I spent a couple of hours playing with my
Pentax Optio W10 in a video mode.
I launched my Sisson Nucleus at the Bair Ranch Rest Area about 11 am and paddled a couple of miles upstream. I spent most of my time paddling upstream and downstream of the rapid above the Bair Ranch. I tried the camera mounted in different ways on a kayak deck with a suction cup (sticky pod) and as a helmet cam.
Shooting movies with the helmet mounted camera was a little bit tricky. I had troubles to keep the camera horizontal, so all my video clips were crooked. Also, pressing a shutter button may be not so trivial when your hands are wet and you are tired after paddling against rapids. I had one or two missed video runs because I didn't start the camera.
I had no problems with the deck mounted camera. I had made several movie clips before using that approach. I didn't have troubles with water drops on my lens since I didn't run any really rough water. For white water or waves some sort of splash cover for the camera may be helpful.
Brad Gwynn makes nice kayak surfing pictures with a Pentax Optio W10 set on autoshoot and strapped to his foredeck as reported in
Sea kayaking dot net. I believe he has some splash protection in his home made camera mount.