I've heard from both Marstrom and Wouter that the curved foils should have a damping effect, but I fail to understand the mechanism behind it? See Wouters text below.

/hakan

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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.
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