You wont get it back, if it doesnt float, not a chance, sorry to say…
A bit late, but use a safety leash next time, it comes with the Quark default also (but not one I would use like it is).
Sorry, just like saying to someone who has lost a board, that he/she should have written name and telephone number on the boards
Have read about different mounts where the cam was lost, so "just in case" I have put a leash on mine too - actually, I have always done that on all kite and linecams
An offset cam here, use a string of line, here Q power line but could be any line, as long as you dont have to put it around your flying lines each time it is easy - took a picture not sharp but you get the idea: