Can't tell from the web page: does the "front tiller" control the lift generated by the hydrofoils themselves or is there some other active control?
I don't see any mention of active pitch or height control, from that I would guess it's just controlled by the rider position and movement, like a hydrofoil surf board.
Reaching speeds of 11 knots - that's pretty impressive. Traditional Bermuda rig sailboats will do around 7 knots on a good day!