wotayottie
New member
I also can't work out how the foil is going to maximise RM at the right time, which is either going upwind or when you're crashed out and boatspeed is low.
You have three factors dont you - the hull shape, the keel and its bulb, and the foils. When boat speed is low going upwind, the heeling moment will tend to be low too and the main righting effect will be the hull shape and the keel leverage. As speed increases the foils start to add righting moment to that of the keel and hull but with increased speed comes increased heeling moment. Likely the designers will have reduced keel weight because the foils help with righting moment. It will all be a trade off but presumably the designer has done his sums allowing for the extra drag of the foils.
But lighter, newer, boats designed from the off to be A-Sail boats are simply faster downwind when sailing angles with a large A-sail than they ever would be sailing deep with a smaller Sym kite.
Why would the sym kite always be smaller?
I sail a boat thats not remotely fast enough to benefit from an asymetric and sailing angles . But leaving aside the boats that are so fast they effectively beat all the time, I have often wondered if a hull that was light enough to fly an asymetic and benefit from sailing angles would be any faster than the same hull sailing dead downwind with a big sym spinny. Say something like a J109 -m if that could be rigged with a sym spinny and sail dead down wind, why would it be slower to the mark than its asymetrically rigged sisters?