da vecta said..
I've just got a black projects type r 40cm and it seems to have a very thick foil shape. It didn't seem to flex nor twist and therefore has little feel. I've only used it once but why are they so fat?
Is the type r a weedy? If so no flex is good, any flex in a weedy is just drag, twist is even worse. It's much better to put up with that stiff feeling than to be wallowing.
Fat allows greater angle of attack, so you can get the same lift from a smaller fin, this is good in weed, the more fin in the weed the more the drag.
And the thicker it is the less flex or twist.
Thin, high aspect, vertical fins are great in deep (choppy) clear water.