RE: Fin for F160 non racer
That's the problem with racing fins I guess; they're not really made for anything but racing angles.. There's no doubt that the R13 will drag less; but if you are really not into extreme angles at all, and if you have decent technicue in chop, the R17 might be something too. I sometimes use it (mine's a S +8) with 11 and 9.5 when the wind picks up but water state is not too extreme. It's very fast and slippery and actually gets great angle when I can keep board speed high. The problem is that once board speed goes down the lift also decreases. This howeveer might not be so much of a problem if you don't need to hang upwind with other racers. Another drawback for me is that I am not precise enough in my footwork to make this fin work well in heavy chop. I tend to overload it and get spinouts (also because heavy chop limits speed upwind and thus lift) - but I guess my 95 kg may have some say here too. Steve Allen was able to wind the WC with this fin on a 160 in very changing conditions, so there's no doubt the fin is ok. If you can find one maybe give it a go?
But still; if you are not racing or anything why not just order the R13-copy that normally comes with the board from SB. It's pretty cheap compared to Debo fins too.