Originally Posted by pgp
So how does that translate into useful performance?

Does anyone know why 6 degrees was decided upon as a rule?


It was done to allow for some development. This allowed for some experimentation but limited the range to a point where it would be unlikely to be any significant disruption to the class stability to have the feature or not.

The 6 degree point also provides a range to avoid nit picking various boats at the time of measure. What are not addressed in most other class rules on this subject are the various tolerances involved in a system. It sounds all nice to say things will be inline or vertical. You have builder tolerances, which if you measure some brands /models can vary quite a bit.
Look at the F18 rules, the boards must be inline with the CL of the hull. The front beam must be straight, but can have the dolphin striker tensioned to provide a prebend. If you have straight hulls and inline boards but tension the striker to full range of the rules, you now have something around a 2 degree inward cant on your boards. You can have more if you play with the trunk stops and who measures this when doing a cert on a boat?