The Stasha can easily be converted 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 which will need to be cut down a little
(full instructions are given or you can buy a kit and make your own sail).
You'll also need a few bits of plywood and an Optimist rudder.
Adding the necessary pieces to the Stasha will add about 6 kilos to the
weight of the boat but since all these pieces are removable and can be
fitted to the boat in the water, it does not affect portability in any way.
Watch videos of the Stasha here