FormulaNova said...
I use these weed/wave fins both in Safety Bay and at Canton:
http://www.surfingsports.com/wardog_fin_designs.asp
I think he's stopped shipping them outside the US though. I like them as they seem to provide enough drive while still being fairly shallow fins. They have heaps of surface area compared to some other weed fins, and the centre of effort seems to be further forward too. I weigh 96kgs and tend to drive the back of the board hard and these seem to handle that.
For a 115 litre board I use a 12 inch, and for my 135 litre board (a hi-fly madd) I use two 10 inch ones.
On my smaller 100 litre board I can use the 12 inch, the 10 inch, or a 9.25 inch one I have got, depending on how fast I want to go and how much lift I can handle.
I've got one of those 10" for my cross117
www.surfingsports.com/freeweed_10.aspI didn't really buy it for weed applications, it was mainly to losen up my board (make it real slashy) Its set forward in the Power Box so you don't really ride it any different - drives upwind comparable to the stock fin (36cm fX) without spinout, but not as fast.
I Wouldn't recommend it as a Slalom weedy.
But that info probably dosn't help answer your question either