Monofoiler
Well, there's a problem with the old adage about semicircular hulls being the fastest especially where a foiler is concerned. The Moth class proved that beyond a shadow of a doubt. While the semicircular hull has the lowest wetted surface, a skinny hull with the same displacement has the lowest resistance.
See the hull section sketches below. The higher length to beam ratio hull is faster than the semicircular hull because it has less wavemaking resistance from zero to foiling takeoff in the Moth class. You'll notice that all fast Moths have a squarish underwater midship section and a fairly high(for a monohull) Length to Beam ratio of around 11/1. In other words, L/B ratio trumps wetted surface in a foiler.
I'm completely convinced that if you're going to race a state of the art multihull you'd better have a state of the art monofoiler! As I think I mentioned before, the Moth beats every multihull around a course and even has a higher top end speed than the Flying Phantom foiler(so far).
The problem is that a monohull foiler must have an exceptionally quick movable ballast system and a 180+ degree canting keel is just not fast enough-especially when it's at near max cant. You'll note that in its last 20 or so degrees of movement the canting keel hardly moves the weight in and out at all, whereas a Trapeze Power Ballast System has just as much weight travel at the end as it does in the middle and can be a lot faster since the weight would only move up a 30 degree or so grade at worst case. But, to be self-righting you would need buoyancy at the end of the racks coupled with a small amount of lead in a fixed keel. But the numbers work out-I've done in several times.(See the sketch below ,done by NFlutter, of my 60' monofoiler concept)
Even with the little bit of lead in the fixed keel the boat will still be a handfull:
it's the rc helicopter of rc sailboats-extremely difficult to learn how to sail-at least my 36" version was. A larger monofoiler would be a lot easier to handle but would still take lots of practice -and probably some electronics-to get the most out of it. You might be able to devise an electronic system to keep the boat at a 20-30 degree angle of heel
to weather, but I imagine that will take a computer guru. You might be able to learn to do it by hand(radio).
One of the great unsung advantages of a monofoiler is Veal Heel-that is heeling the boat to weather up to 30 degrees when on the foils going upwind.
The boat can gain about 40% of its righting moment by learning/designing the boat to sail this way. Thats 40% of righting moment it doesn't have when its
level!
Some of this stuff may be hard to understand but believe me it is real and has tremendous potential. Good Luck!
If I can help just ask......
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The following two links might give you a grounding in the theory of how a foiling keelboat is possible:
My 60' monofoiler concept:
http://www.boatdesign.net/forums/sa...acing-monofoiler-design-discussion-15143.html
My 30' foiling keelboat:
http://www.boatdesign.net/forums/sailboats/foiling-keelboat-30-a-38395.html
