ColoColo said..
I saw this on ebay just browsing.
It's a brilliant idea.
http://www.ebay.com.au/itm/Restube-life-saver-for-all-watersports-users-/222154575492?hash=item33b971ce84:g:oH8AAOSw3xJVVX15
A bit pricey, and probably one could make one using those Co2 canisters that cyclists use.
But considering how scuba divers have a "safety-sausage" if they too get into trouble and drift out to sea, I reckon this sort of safety should be a minimum in kite surfing.
this is really only applicable to those who go way offshore