The Fliptail can easily be converted at any time to a great little sailing boat if you wish.
Full instructions are included for free in the plans.
You'll need an Optimist mast and sail and also need a few bits of plywood and an Optimist rudder.
Please note, the Fliptail 6 & 7 will need to have the Optimist sail cut down a
little (full instructions are given or you can buy a kit and make your own
sail).
See some videos of the Fliptail
here