I know this is a late response to your post, but what we use when we go to the lake is 960 at 48 fps. If I had a black, I would be shooting at 120 fps. The higher fps the better. you can take the video, edit it, slow it down, speed it up, everything and it will stay smoother than a lower frame rate.
For surfing, you can use the suction cup mount and it will work very well. However, if you want cool angles, go to Home Depot, buy you a 1 inch or so piece of PVC, a 90 degree elbow, and end caps to seal it so it stays air tight. Cut the PVC in a short piece, maybe 3 ft. and attach the 90 degree angle. Then cut a smaller piece off the extra PVC you have and attach that as a grab handle. Cap it up and boom! instant GoPro pole! As long as it's air tight and you have the GoPro floaty, it has a better chance of floating. Next, go to Best Buy or your local store carrying GoPro Equipment (Target does too!) and get the GoPro Handlebar Mount. Mount that thing on the pole, which ever side you chose. But you can be better on the safe side and get a noodle from Walmart and zip tie pieces of that in a few places so it floats in case you drop it. With the pole, you can have someone put it out closer to the rider, get real cool boat shots, and just have over all fun with it.
For wakeboarding, I will say mounting it on the tower with the extreme wide and fixed angle lens, the rider will most likely be really small. It's definitely doable by all means, but it will be small. I suction cupped my GoPro to the back of the boat for rider shots.
check out the video I shot soley with GoPro Hero3 silvers. This will give you a good idea what you can do with it!
Just get creative and have a good time!!