firewire deviant fin

saw some post in november about this ...but heres their official blog...looks interesting

so we have the marriage of two of the greatest minds in swaylocks history in one fin!

blakestahs rotating fins and Roy’s tunnel fin.

god help us all!

Blakestahs fins changed the toe angle, these change the cant. Interesting that there is no pre-loading in them at all. They just flop around through 14 degrees of cant until they hit the hard stops on either side.

Same concept of having cant on the rear fins in a quad.

Looks interesting, but at $50 for a single center fin, that’s a pretty
high buy-in.

Mentioning Roy and Firewire in the same thread, inviting disaster :smiley:

So it’s essentially a loose, flopping fin?


As much as it sounds like a bad idea, my buddy has an 8’6" single with a fin that flops in the box (appx 10-15 degrees total travel). you can feel the fin wiggling when it’s unloaded, and then lock in when intitiating turns or setting trim. Just a magic board!

I’ve never seen/held one, but to think it will be floppy is misguided. Most of the time the fins are loaded, heavily, and they will be pushed to the end of the range pretty fast. They PRESUMABLY had to engineer it to be quite strong to prevent breakage (an issue I dealt with also), and to soften the ends of range so it doesn’t slam into position. THEN there is the question of whether it improves the ride or not. Be interesting to try out…


The Deviant Fin has recently been made available for $35 including shipping and handling in the USA through the Firewire site.  Out of curiousity I purchased one and have tried it out once at a break I frequent on the north shore.  The waves were quite small, waist high with decent shape, kinda hollow breaking over a shallow reef that ended in a deep channel.  How did it feel?  It felt like the board was a little quicker through manuvers, whether turning, coming off the top or cutting back.  It did'nt feel like the hinge at the base caused any drag or lag when the fin went from one angle to the other .  While there was'nt a huge improvement in performance, there definitely was a little and I'm hoping that when I get it out in better waves, this fin will perform up to the manufacturers claims. 


Hi everyone !

I haven’t posted in quite a while, but this new Deviant Fin has really made me excited again about surfing.


I used to experiment with fins quite a bit, altering foils and such, and testing the impact on a board’s handling, as I had great consistent waves to test them out in, in Hawaii and the South Pacific.  Sadly, my surfing has taken a backseat to work the past few years.  I even lost a lot of stoke by having to resort to riding slightly fuller boards to compensate for lack of water time.  Ok, but not the same as riding Ferraris.

The board I’d been riding most, was limited to slower arcs than I was used to.  On a whim, I picked up a Deviant Fin and was immediately impressed- the tighter arcs were about half of what the board previously had.  It seemed to chop off four inches in board length. I’m totally re-stoked.

The theory is sound, reducing resistence by allowing the center fin to match and not fight the rail fin.

Quads have a similar front turn feel, but I hate their lack of pivot compared to a Thruster. This concept allows the best of both worlds: speed of a Quad off the first turn, but way faster cutbacks and turns than a quad or a thruster.  I recalled seeing an old Larry Bertelmann film clip early seventies where he rode a loose fin (single) on purpose to reduce arcs, and that always stuck with me as making sense.


I just finished filing down a normal FCS G5 center fin’s tabs so they’ll be loose in the box, and drilled holes in them so the screws can hold, and I can’t wait to get it out for testing to see if it works better by eliminating the large bump in the Deviant Fin.  If it reduces drag and goes even faster, then that will be even better. I am very surprised I have not noticed any added drag in the Deviant even with the hump, though.


One caveat: if a board is already loose it may not go at all.



I don’t think it makes the board go faster, but added a bit of maneuverability on one of my drivey boards that wasn’t loose enough, and seemed to maintain speed through turns as well, and didn’t get sketchy feeling like when sometimes trying to loosen up a board by reducing fin size, overall I really liked it but I suspect you will have to choose the board that you use it with carefully to get the benefit.  Shame I ended up losing the fin, but it was good enough to consider buying another one.



I got one, the idea of it sounded good, but to actualy use it, was not so good, difference is very minimal…I have a range of fins and will just tweak my varied templates and doubt I’ll ever try the deviant again…maybe if it was made to change things alot more than is able on this one, then that difference could be come a benefit…just my opinion…