Up until now, I've used the chest harness to record while wakeboarding or wakesurfing. This weekend, I attached mounts to both the surfboard and wakeboard, using the surf accessories. For safety purpose, I have a tether attached to the camera. On the wakeboard, the other end of the tether attaches to my binding. On the surfboard, I used two (double protection!) of the tether sticky mounts. so basically it's attached with 3 (main and two teather) stickies.
Here is a shot from the surfboard and the wakeboard, coming into the wake for a jump. Water spots were an issue and I need to put something on the lens to help with beading.