Listening to the comments surrounding the teams, my guess is that they are going to be shooting for a semi-foiling mode off the wind and a near full flotation mode upwind. There is a happy point between weight, available power, and efficient foiling. I think the Moth's are just able to come in under this point with one very light (single-hull) boat so they can foil all the way around a race course efficiently. I don't think we have the technology to have a boat light enough to do this on much of a larger scale yet. While we can definitely build a catamaran to foil to weather, it's suffers with wind and water drag to carry it's own weight. It's going to either sail slowly as the foil drag increases with reduced speed or have to sail so far off the wind in order to keep enough power to stay on foils that same water-borne craft will get to A-mark faster because it can sail much higher.

So, if you give up fully foiling to weather, you have to look at how much foil drag you are willing to carry up to A-mark so you can rocket downwind. My bet is that the happy-point is going to be having just enough foil to make the boat really light on the water while going downwind without becoming completely air-borne on foils. This might also make sense given the fact that they aren't allowed any type of active control surfaces under the water and their racing area is a really choppy piece of water.

The "S" boards on NZ are a good indication of this as well (they can change the angle of attack of the horizontal part of their foil as they lift it).

Then again, I could be completely wrong.


Jake Kohl