I didn't want to stick a mount to my mtb bike helmet for fear of ripping the paint/graphics off, so I used zip ties. Been working quite well.
Make sure that you have the right back on before going in the water! Very easy to kill it if not.
Get a battery bac-pac, you'll need it. If you strap it to a kayak or anything where it can go flying, tether it!!! You have been warned.