Ahh finally some factual argumentation (when in only part of your post anyway)




I'm convinced that if the banana boards are proven to have a "large" advantage that the A-class should adopt this feature fully. I don't think the old boats are made obsolete that easily and if they are then I also don't believe this to be a major issue for the class. Mostly because local fleets will transition much slower then the top of the fleet who are changing boats very often anyway. Also a curved daggerboard trunck is quite an acceptable modification to any older A-cat. It is on a par with upgrading to a new design mainsail in cost. And nobody when ballistic over that either. And again, I think such a step to be comparable to the carbon mast introduction that obviously did not kill the class or prevent it from growing internationally.

I think the core of the class is the active racers at the top. Keep those on boards and the recreational sailors will follow anyway despite pretty vocal declarations to the contrary. I refer to the Tornado upgrades as a prime example of that. 2/3rd voted the changes down but 2 years later over 2/3 ofd the fleet had changed to the new voted down setup anyway, with the class now just as strong as before.

I truly and honestly believe that the core of the A-class is largely unregulated development. Without it the class would have died as a 100 kg alu masted single sail singlehander years ago. Another class like the inter-17 or F16 would have replaced within 1 or 2 years of its introduction. And that has nothing to do with either the inter-17 or F16 class and all with the inability of such an A-cat class to remain exiting in a scene where other classes progress to new levels of performance and attractiveness.

In fact, I will even be a large supporter of allowing curved boards in other classes like the F18's and F16's once the design has stabilized. In a similar way the square tops replaced the old pinheads.

As an engineer however I don't see curved boards to be able to result in a "large" performance gain. There is not enough percentage associated with the hulls in the old-fashioned setup to justify such an improvement. Of course the drag related to the (straight) daggerboards remains as this is closely linked to the sail force of the rig that isn't changing in any significant way.

I classify the curved daggerboards much more as a refinement then a breakthrough. This because its effects are far more in the field of damping the boats movements then lowering the overall drag. I also feel the latter is already partly adressed by inward canted straight boards. (whatever happened to outward canted boards guys, the hot and exiting development of a few years back ?) And there are some conflicting design problems that are not obvious at first glance. One of those is that simply curving inwards the boards doesn't do that much to lift the boat when the foils are symmetric. In the way of damping movement they will be effective that way. In order to create meaningful lift (in this case, enough of it to matter) assymmetric profiles are needed or a permanent angle of attack of say 4 degrees. At low speeds or when having two boards down these characteristics are actually a disadvantage. That is why patient lady C-class design, raised one baords and lowered the other after each tack. Patient lady is one of the very few examples of a sufficiently succesful implementation of curved daggerboards as a performance enhancing item.

I think I have answered all your questions.

Wouter