It works different. A boat with angled board or asymetric board will actually point lower while travelling the same path over water - only faster.

The benefit is that angling the daggerboard (or using an asymetric one) changes the yaw attitude of the hull so that it will use more "foil generated lift" and less "hull generated lift" to keep forces in balance.

Since the foil's lift/drag ratio is far better then the hull's lift/drag ratio, the total drag is reduced and the boat can sail a bit faster.

A secondary benefit is that, due to heading lower, the sails can be trimmed at a higher angle of attack to the wind, also improving speed - or enabling to point the same as a normal boat, but travelling over a better (higher) path upwind.

Take a look at the self-explanatory picture. The asymetric section daggerboard could be an angled symetric daggerboard as well. The difference is negligible.

(note: the drawing does not show the "hull generated" contribution to lift in the conventional boat diagram, but it exists)



To Klaus: the difference between the lift/drag ratio of an asymetric and an angled symetric foil is tiny compared to the diference between any of them and the lift/drag of the hull generating lift at an angle of attack. For this reason, the choice of an asymetric or angled symetric foil would be almost irrelevant.

Still, the angled symetric foil is better because it self-tacks upwind and become a fixed symetric daggerboard when raised (even slightly) upwind, while an assymetric daggerboard will require active management in a cat.

On the other hand, the asymetric board will alwasy fit the cassette perfectly, while the gybing board will leave a gap between its leeward side and the cassete wall when fully down.

All the best,