07 Jul 2023
You might have heard about them, seen them, or even ridden them, though if you did, there's a good chance you're still riding them! I have to admit, when I first saw a set of AU fins, I was reminded of Kevin Costner in the movie "Tin Cup"....there's a point where he's lost his mojo on the golf course so he's resorted to every contraption invented trying to find his groove again. He looks ridiculous and at first sight I thought the curve of the AU fins was ridiculous too, a gimmick at best. I'm here to say, it's science!
My buddy who brought the fins down tried them and he couldn't tell if there was a difference. He admitted though, that because he only surfs on vacation a few weeks a year, he probably doesn't have the ability to feel the difference. He offed the fins to me to try out the next day. My first wave was nothing but a couple of turn and the fins felt different, maybe slightly more twitchy, but it wasn't until the second wave that I had an interesting breakthrough. The second wave was more down the line...I had to race it, so I turned mid face, started pumping, staying high in the pocket and driving...the fins were engaged and solid and seemed to squirt me along with every gyration of my legs. I think with my regular fins I might not have made it around those sections. I wasn't sure though and so the next day I went back to my old trusty CI / AM2's. I've been riding these fins with confidence for years and I've only strayed a little from this full bodied design. I'm a big boy at 220lb's and I like big fins. With the AM2's under me the next day I felt normal again, but I did feel as though I was lacking a little speed....as though I only had a 5 speed and was missing that 6th gear. It wasn't disabling but it was suspiciously notable, though I was skeptic if I could truly notice a difference. I had brought the AU fins on the boat and went back and made a swap mid session. At that point it was like a light bulb going off...from the very first wave I could feel the fins were faster, notably faster...5%, 10%, 15%? I don't know how to quantify it exactly, but it was an absolutely tangible difference under my feet and in my surfing. The handling characteristics were slightly different, but not in a bad way, I adjusted within a few waves. In small barrels when I was squatting and unable to pump, I was very aware of my ability to hook the fins up into the highest part of the wave, to the point you could feel them squirting you forward even as the foam ball was pushing up under the tail of the board. During turns, if you leave the board on rail, the fins hold as any other fin would, they don't seem squirrely and they don't seem unstable. Of course if you want to release them, you can flatten your board out a little, disengage the rail and slide as far as your momentum will carry you. The fins re-engage quickly and I swear, they let you hold a slightly higher line when you're driving down the line. The offset that the curve gives is maybe a centimeter or two...but that little curve in the fin seems to hook up, just a little higher in the face of the wave and from there you can draw your own conclusion...it's grabbing a little more energy and giving you a little more drive. In the end, that means more barrels made!
Edit Image The AU website has their own marketing speak and they talk about "spiral propulsion technology". Their tank testing and hydrodynamic equations support the fact that the curve of the fin reduces the vortices created by lift, which is also equal to drag. The more lift, the more drag. In this case though, like the winglets on an airplane wing, the curve seems to keep the laminar flow just a little more "flowy", there's less deflection toward the tip of the fin were lift is lost to drag instead of acceleration. It sounds like mumbo jumbo, but when you can feel it under your feet, it's hard to argue with.
There are probably some opportunities within when it comes to board building and setting these fins, I think there might be some things to consider with regard to cant and tow in. I can't begin to pretend to know what's best, but it might be a discussion to have with your shaper and bit of a trial and error to get things right depending on the board you're designing. For the boards I've got the AU fins in now, a 6' swallow tail daily driver, a 6'6" thumb tail step up and a 7'6" "puerto gun", the fins work wonders on all of those.
Keep in mind, I've not received anything for writing this review...I have no relationship with AU fins other than I'm a new customer. I hope they are a great group of guys because I think they're going to make some money off this great technology and I'm happy to support them...especially if they're cool. I've since bought three sets including The Hybrid full base 2.0 quad set and two sets of the LRc full base quads....these are carbon fiber, black, sexy with gold lettering and look good on any board. I have no shortage of questions and interest every time guests see my board in the board rack on the boat, or in the lodge. I'm a big a fin geek as just about anyone and I can safely say I'm worried about my futures.
I have a wall full of future fins that I've collected over the years...and they might be obsolete for me now. My next board is a step up that I plan on having made as a twin fin with channels...the fins I'm going to use: AU Kilos twin...it's a small keel fin with that sexy curve that says I'm going to go faster. I don't know about you, but too much speed is rarely a problem that I'm not happy to have...nothing a check turn or snap stall can't fix to get me into a barrel. I certainly believe that my AU fins give me the best chance of getting the speed I need to make it out.
If you want to try out a set of AU fins, come for a visit to Sirena Surf Lodge here in Nicaragua and I'll loan you a set. I only have futures, so bring a board you like with future boxes, or you can try them out on one of our house boards. Like I said...I have no incentive to support AU, I'm just happy to see good innovation that produces real results. Get some!