Yeah , your right Terry . Jim did swap it out for his squared off "Ginsu" as he called it . I'm guessing since more and more boats are being updated with the squared ones there is no real direct relation between fin shape and hull .
My theory is that the shark fins type being the earliest designed to have the water follow the trailing edge or tip and not disrupt water flow . Try to make it as efficent through the water as possible
The traditional squared/trapazoid shaped ones like mine , from what I've gathered are a knock off the outboard guys . I really think you'd be hard pressed to find a better group of guys to copy a fin from than them . I dont know specifics on leading and trailing edge angles but I'm sure a whacker guy will tell you .
Ultimately , I think the sacrafice in speed to surface area is minimal and now we're seeing the big rectangle shaped ones with only the leading edge angled . Of course the most surface area for more bite and even doubles on the racing flats .
Of course my theory's are based on conversations I've sat in on with a few folks and forum descusions as well .
-beerjet-
