RE: what fin size for a 6.8m on a S type104
Earlier you made the following statement:
"In any case, publishing the area of the Drake fins can't be a bad idea. Then people can do with this information what they want."
This is getting to the heart of the matter that I commented on earlier. Information is a good thing, and it creates broader base or dimension that folks can reference. Like Del Carpenter, I'm not one with a scientific mind that gravitates to formulas to figure things out. Nonetheless, I still like specifications because they tell a story of sorts. A wealth of simple facts can help us ferret out a path. Personally, I find inituition one of my best guides, particularly when the visual shape of something is revealed. Still a lot of trial and error is possible in conclusions, but there are lessons in that.
In parting, I think drzone is right on in suggesting that Starboard outline aspect ratio, fin length, thickness and surface area. The only other additions I would suggest would be fin material, to include photos/drawings.