RE: what fin size for a 6.8m on a S type104
Thanks to each of you for the good discussion. I'm one of those average (or less) skilled guys with quite a few more sails than fins. Dolf's formula interests me as a general guideline. It was presented as a formula for determing the "minimum required fin area" needed. Dolf, do you have a formula for determining the maximum useful fin area? And does the length of the board change either formula? My knowledge of the physics involved is minimal. My intuition tells me there are formulas that apply. And my intuition also says the differences between my 372 cm long Equipe and my much shorter X-186 should mean there are significant differences in the formula's I should apply to each board. (I don't remember the X-186 length, I think its about 270-280 cm.) Maybe overall length doesn't change the formula but planing surface length would? And wouldn't the board width in the fin area also change the formula? Again this is just my intuition, I have no theoretical or applied experiments to back up those ideas.