I've watched a bunch of GoPro clips where the camera is attached to the ski looking back at the skier, and I really like the perspective. I've also noticed that in alot of those clips the ski bounces hard enough to move the camera (most of the time causing it to point at the top of the ski). So when I got a GoPro from my wife for my birthday I knew what I wanted to try first. I mounted it up with homemade float attached to the back. I made sure the set screw was as tight as my fingers could get it and hit the water. By the second wake crossing the camera was facing the ski and not long after that it flew off the ski (good thing I made the float).
Here is my solution. In addition to using a screw driver to snug up the set screw (not so tight as to break the plastic), I made a new wedge shaped float with some extra velcro on the bottom side and a mating piece on the ski. Tried it yesterday and it worked great.