I have a plastic fin for my board and i've been told its awful. Until such a time arises that i can buy a new fin, could i increase the performance of the fin by trying to improve the shape of the foil. Will i see any noticeable difference or am i just making a bad fin worse?

Apart from the obvious, the sailor...

If you are reasonably powered, hence the sail size is fine, what are the major factors contributing to the speed?

How much will a type of fin contribute to the speed?
The boards? Sails?

I'm looking for a decent weed fin for my new (5 years old ) board.

I got some great advice on this forum for my other board (115L) and I was hoping for I can get some help for this board.

JP FSW 98, 6m sail, weight 97kg.
Target area - ocean at Pinnaroo Point - bump/jump
Skill - still not gybing...

So far, I cut this:



to look like this:



And it worked...mostly...I can go fine, change direction, feels controllable
...except when it comes out (I.E. a small jump). It loses grip as it comes back in and keeps sliding. I should get something decent instead.

Can anyone help ?
Thanks in advance,