Looks good but no harm besides possibly losing your GoPro. Why not teather it to the back footstrap with a wire trace?
Enjoy your windsurfing. How do you get so much time to do it? Self employed? I used to be but wasn't windsurfing much at the time. Now working full time, earning less money and I am windsurfing. I'm a fool.
Can't wait to see you with cameras fly mounted to the mast and both sides of the boom, sticking out the back of your harness and on the back of the board. I think next you'll have to get yourself a remote controlled drone to hover around behind you
