I can't remember the exact details, but from what I remember there is some kind of mount that goes in the leash mounting hole, and some people attach a pole to it to raise the perspective. You might be able to get away with something adhesive, but I'd only really do it in calm water and definitely use a leash that way...
I've had an opportunity to work with some guys in Maui on a prototype. the idea was to take it into jaws but not sure if they've tried it yet. I can tell you it better be built solid if you're going to take it into the surf. I won't tell you how it was constructed in detail, but I will say that the base was built so it would fit into a futures box which was to be potted on the top deck of the board. I'll check in with the photographer to see if he's had a chance to try it out or not.
BTW a couple years back, I developed a leash plug adaptor that allowed me to mount a gopro via my fin mount over the leash plug area. what I did was machined a custom "J" nut. this had a small hook on the bottom end and a threaded hole on the opposite side. I would than have a base plate with a hole for the bolt that I could put against the top deck and when I tightened the screw it pulled the hooked end against the leash pin. this worked well however did not get the perspective you are wanting with an elevated position a couple of feet above the deck.
Thanks for the info. First of all, that footage at Jaws would be RIDICULOUS! I want to check that out. The leash plug idea sounds interesting, i might fiddle around with something similar. I mainly want to use it on my SUP because it will be in small, mellow waves but the idea of having something similar for big open tubes would be awesome. Similar to Bryan Connely's movies.
I don't really want to drill through the glass of any of my boards if i don't absolutely have to. I might just have to give it a go and see what happens. Im thinking some baseplate with an adjustable pole (maybe from a paint brush extension) and a gopro accepted mount on the top. Ill post some images if i get around to it.