How fast can it go?
In 2-3 knots of gentle breeze, it ghosts along.  It becomes perky in 5 - 8 knots, and planes at 15 - 18 knots of wind.  (Note that its small size makes it feel like it's going faster than it really is.)

How many people will it hold?
The Wingsailer handles 300 lbs., but sails best carrying 175 lbs. or less.

Does it turn over easily?
No.  Because a wing is more efficient than a conventional sail, the Wingsailer heels less than other boats.  So tipping is less likely...

Wingsailer Specifications

LOA (Length Over All):      10' 3"
LWL (Length Water Line):   8' 6"

        Beam:   4'
        Draft:     3" with board up;
                      25" with board down

               Hull Weight:  approx. 60 lbs.
               Wing: Latham Wing