I think boards/no boards rule is sufficient.

After all between my very low aspect Taipan boards and the best F16 high aspect boards there is currently only 1 % rating difference.

However I do find that my boards are better in big wind then the tall skinny ones while in midrange winds I'm at a slight disadvantage. In the really light stuff we are equal again. Also because my V-ed hulls handle light winds better then the hulls with rounded keellines.

So I see it more as as trade-off between mid range winds and strong winds. Ergo neither board design has a clear advantage is ALL conditions. It will therefor average itself out over a wide spectrum of conditions. Then the KISS principle kicks in. There is too little to be gained in increased fairness against to much added complexity.





Partly, certainly in the current form. If anything then make all daggerboards the same and have a seperate hit for pivoting centreboards/skegs and then another for asymmetric hulls (no skeg). This maybe too simple but I do feel that 80 % of the differences are well handled by a simple rule as that. The remaining 20 % is measured in less then 15 seconds per hour and not worth the trouble.

We'll see all modern boats come out with daggerboard aspect ratios between 3 and 5 anyway. In the engineering literature that I have the difference between these aspect ratios is not too large at all. Beyond 5 there is hardly anything to be gained. If you do a hit calculation on aspect ratio 4 then both 3 and 5 boards are too close to 4 to be noticeably different. This is the "halve way value = close enough" trick and works suprisingly well.

Pretty much think of it this way. Roughly, the difference in lift/drag ratio when going from aspect 2 to aspect 3 is of the same magnitude as going from 3 to 5. And additionally the difference between 3 and 3.7 is the same as going from 3.7 to 5. So very quickly the gains decrease with each added point of aspect ratio.

That is what I would do. Actually that is what I have done as the F16 rules didn't consider the boards to be worth ruling upon.

Currently I'm working on some new daggerboard design for the F16's and we have decided to not go over aspect ratio 4 because there was not enough to be gained there for the extra effort required to make such a board lightweight and stiff. Additionally it means that a singlehander can pull the boards up to an optimal exposed area and still get an effective aspect ratio of 3 or higher. That was the compromise that we made. Aspect ratio of 3 is probably the minimum you want on a modern boat, below that you start loosing increasingly more performance.

I hope this helps.

Wouter