Using the Orma 60 footers and AC cup boats are a poor example, the C Cats and A Cats are probably the most developed of the boats using C Foils nearest our water line length and they really are not convinced.

The other factor no one really has mentioned yet is what happens in normal sailing wind speeds around the, 8 -12 knots band, small foils such as the F20 uses are in no mans land, neither creating enough lift to reduce wetted surface and yet must be creating drag, ( you cannot get lift without creating drag ), I do accept there must be benefit once boat speed gets to a point but in general that cannot be the norm. I do accept that the T foils on the Stealth for example can sort of defy logic.

I am a foil convertee however and I do believe all new design boats will go down this path and the more the likes of the AC and C Cats develop the foils we can only benefit in the smaller, size wise, classes.

Wayne, you just keep coming back with stuff that's simply wrong! The F20C is performing at its biggest advantage in the 8-12kt range. The foils are working to lift the boat and the leeway is minimal. As an Example here are some time from a recent regatta in NED:-

Wind 8-10kts
3 laps W/L
1st. F20c elapsed time:- 44.39
2nd. F18 elapsed time:- 54.30

I was there and can tell you the worst thing about the F20c's performance in that race was the long wait for the rest of the F18's to finish!

Did you see Steve Clark's boat in the first race in Newport? (before the crash..) that thing was smoking fast..

And to discount the development in bigger boats seems a little silly, There have been a lot of things developed in the AC that scale down very well, Have a look at the Hulls on the F20C and compare them to the floats on USA17.

I guess one could do a 18 sq and see what happens.. Or even a F18 and screw up their old fat slow is best mentality...

Well since this is a F16 forum and at this point its against the rules .. all moot and waste of pixels

Macca read the posts carefully, to repeat myself "I am a foil convertee however and I do believe all new design boats will go down this path and the more the likes of the AC and C Cats develop the foils we can only benefit in the smaller, size wise, classes ".

Yes the F20c's appears a fast boat ( sort of remember that it didn't do so well at the 3 Piers race this year ) but how much of that is hull shape, a combination of hull shape and foil or just the foils alone. I guess time will tell us one way or other.

Wayne, wasn’t it you who was debating here about making the boat easier to sail for the average and beginner sailor?
I had several foil discussions with a couple of the C class guys when the A class first began this debate. Their view was that they were not really able to improve performance effectively over straight foils in anything but a relatively narrow set of conditions. And, application to even smaller length boats like the A would make this even worse. 4 years into it and the A debate remains in limbo. Even on the 90 Dog boats the curved to straight choice followed a very specific conditions window.

Using the very simplest physics: If a curved dagger provides lift, it will do so with a bow up position theoretically reducing the wetted surface some at the expense of some additional foil drag. Place the hull in a bow down position and you have both drag and additional wetted surface as the boat is pulled down into the water. A 20 usually is more stable than an 18 or 16 but still crew skill in maintaining the proper attitude is critical to making the boat go and several orders of magnitude more important having curved foils.

At the end of the day, you have a boat that is debatably faster in certain range conditions, but is even more technically challenging to bring to its peak performance and less applicable to the new or average driver.

But you have bling and something for the technowiennies to debate endlessly on forums.

Matt, at this stage of development I totally concur with your last post. However I do feel that we are at an early stage of development and mainly through the bling factor and the marketing mens desire to be one up on the competitors, it will become rightly or wrongly defacto for all new designs.

When I was playing around with gliders in the 80's the big new thing was "winglets", huge huge debate on their worth at the time but they did prevail and all new designs have winglets of some form or other now.