On my xp I used the standard go-pro sticky mount with the 3M backing It was really stuck on there, and I suspect it is still stuck on there 4 years since I sold the ski. However, if the camera was mounted and you gave it a good slap, its likely coming off, you can buy aluminum mounts (slightly curved, for helmets and such) that bolt onto the hood (or wherever) but I didn't like the idea of drilling holes into the plastic.
The 3M was much more solid than the suction cup IMO.
on my next ski, GP1300R I used a handlebar RAM mount from gpscity, it's bolted on there solid as concrete, AND it doubled as a gps/phone holder if you purchase the correct adapters, so 80% of the time I mounted my etrex gps there, and 20% mounted my gopro.
I'd poke around and look at the RAM mounts If I was looking again, I sold my gopro after about a year.
Why? I had collected over 50GB of video, hours and hours.... but realized that I had neither the patience, the right software or the right computer to properly edit footage. Most of my final footage was simple 30 second clips I pulled out of 20 minute long video's, the rest just sat on an external hard drive. I found editing video to be ridiculously cumbersome and I didn't have the right mindset.. perhaps you are different in that manner.
I only mention that to make sure you don't overspend on go-pro and accessories only to end up realizing 6 months later that you really DO anything with the video.
my ram mount side view with the gps on it, as you can see (I hope) you can move it up/down to adjust for whatever your doing and you can pop the mount on/off the ski while idling in about 10 seconds and toss it in the glovebox.
front view
hope that helps.
ps.. downside to handlebar mount, you can only see stuff in front of you, and the view moves left and right as you move your bar's, so technically the hood is a better choice for keeping things in view, but still kinda tricky to view your buddies on the water. I actually only used that bar mount for river twisty runs, most of the time I held onto it and panned left and right for a few minutes then shut er down and tossed it back onto the bars.