I had a very mushy/under powered session on my 102L FSW board and my 5.3 wave sail yesterday using a 24cm K4 3SW (powerbox) fin for the first time. Conditions were cross/on 13 knot occasionally gusting to 15. Pickings are slim at the moment with early signs of the doldrums. Water was wind generated chop with very small swell and very weedy.
I'm really happy with this fin. I was only just marginal, but still had a good time. I was upwind, and planing most of the time - happy. The only down side, is my local is very weedy (the weed is similar to 0.5m to 1m x 5mm fettucine, except the fin can't cut it). The wind wasn't strong enough for regular jumping, and fin would stall and spin out as soon as it caught this weed. But hey, it's not a weed fin !, and it's better than my current weed wave fin, which feels like a pig compared to this fin.
I purchased this fin, because it's swipt back (just like the Makani KAKU - see later). The fin guide recommended a 24 or 26cm. I choose 24cm to make it more weed resistant.
A bit of background. I've been a long time user of 22cm Makani KAKU fin (5 years in fact). I use this on a 85L FSW board with a 4.7 and love it. Not only is it well performing, it's short size and swipt back shape make it very weed immune. I never have problems with weed when using this fin. Unfortunately Makani do not make the KAKU anymore and there is nothing equivalent in their range (Bloody hell Louis, how can you do this to me !). I would have loved a 24cm KAKU and if I could get one, I would be reviewing a KAKU instead of a 3SW.... anyway, that's aside....
To compare the K4 3SW fin to the 25cm Unifiber Power Wave fin (power box) I brought two years ago, the Unifiber Power Wave is a piece of ****. I had two "humming" runs (that's what the fin sounded and felt like) on this Unifiber fin, and ended up down wind. It felt flat and unresponsive with no ability to point. After a beach walk, I removed it and that was the end of that !
I could go on with my jinxed experience with 24-25cm size wave fins, but to say, the K4 3SW fin is the first wave fin in the 24-25cm size I really like.
