One of the things I look forward to most when attending Surf Expo every year is the possibility of finding something new for my paddle boarding business. I’ve learned over the years that it is not as easy as it might seem to do this. We tend to look for products with high quality, style and most importantly astutely functional.
This year I stumbled upon AU Fins - a small booth with just 2 guys working it. The booth setup was as basic as it gets with a table with some fins. What stood out was the fin design which was unlike anything I had seen before. At first glance the fins looked like someone left their board inside their car on a hot summer day and the fin began to melt.
Researching the history of curved fins and you will find that the concept is not entirely new. FCS has the Greg Webber PC-CRV fins from a few years back. Future Fins also has a curved fin with a subtle curve in it. You may also come across the Turbo Tunnel fin. While not a curved fin per se, an interesting looking design for sure.
Either way none of these curved fin shapes have been widely adopted by surfers. That said the AU fin design is unique, particularly the shape and location of the curve (i.e., midface as shown below) in the fin when compared to these previous versions.
Looking up the company, I found the design was born on a surf trip to Indonesia more by accident than diligent research and engineering. What makes it work is based in the hydrodynamics. As water moves through and over the curved fin it creates lift which theoretically gives you more speed down the line. The curved shape also locks water in under the board which gives you stability at speed.
So far it seems only surfers, for example Nathan Fletcher, Kalani Robb to name a few, have tested the fins. The feedback has been positive. Surfers reported more speed, tight turning and solid grip when carving power turns. More speed and stability at speed are things that every surfer wants especially an east coast surfer. I did read that they can be a little sticky coming off the top. Other critics claim that the "vortices" created from the curved fins cause drag. Lastly, a number of folks have questioned the gold color in the design. Like it or not, the inventors of the company own a gold shop – hence the AU in the name. AU is the symbol for gold on the periodic chart.
While it may not be a new or proven concept, the excuse "we've tried that already" doesn't hold much weight with me for a number of reasons. Considering I found nothing on how they might perform on a paddle board, I decided to give them a try.
I enjoy experimenting with different fin configurations and fin types. I was excited to expose myself to the "hydrodynamics of spiral propulsion" on two of my favorite paddle boards (SUP) – the NAISH Mad Dog (8’6” x 29”) and the Nalu Carbon Pro (10’ x 28.5”). I must say the black and gold design looks sweet on both NAISH paddle boards.
For perspective, I am 195 lbs, been paddle surfing for 7 years and usually ride with a quad set up. Conditions here in Fernandina Beach (N FL) consist of semi-hollow and fast beach break.
Day 1: On day one of my testing, conditions were waist high and semi glassy with a bit of cross swell making it a little bumpy. My board was the NAISH Mad Dog. On my first wave I could clearly feel the speed was there as well as what felt like some extra side bite as I pumped down line on the semi hollow face. The speed increase was by no means dramatic relative to my usual quad set up but noticeable. The extra side bite was nice as on small fast waves I have had my tail break loose especially if I get too aggressive trying to make a section or stay in front of the white water.
Lastly, I also noticed the tail of my SUP felt locked in place (i.e., sucked down) as I turned down the face at maximum speed. At this point I am not sure how to interpret this locked-in feeling - stability or drag. I look forward to seeing how this impacts performance on bigger waves with more speed.
More to come...