Thanks to Keith at Hawaiian South Shore, we got to take out one of the more interesting fins on the market, the Wavegrinder. The fin has been around for a few years and we were excited to take one out in the surf for some stand up paddle surfing action in waist to shoulder high waves on Oahu's North Shore. In this Finsights article, you'll learn what the Wavegrinder is and what we found as the pros and cons of the unconventional fin.
The Wavegrinder fin is an angular upright fin that draws on technology and hydrodynamic principles used by the yachting and airplane industries. The pronounced feature of the Wavegrinder is what they call "winglets". These are small wings near the tip of the fin designed to reduce drag and increase lift.
Without reading too much about the theory behind the fin, we tested the Wavegrinder fin on a performance stand up paddle surfboard under 10'. We were more concerned with performance than theory, so truthfully, we'll read the complete story about the theory behind the fin after we finish the review. We ran it as a single fin, as we understand it was meant to be run, and set the fin about 1/2" from the front of the box.
The fin is constructed of a clear blue molded plastic and comes in one size, 9 1/4". The leading edge is smooth and seamless and the trailing edge is quite sharp. You definitely wouldn't want to run into the back of it. It's clear that precision molding is a high priority for the company. The installation screw is in front of the leading edge of the fin. The fin is very lightweight.
Installation took a little more work than we anticipated. The diameter of the hole for the installation screw is smaller than a traditional fin screw. To install the fin, you must use the screw and screw plate that comes with the fin. This means that to install the fin, you'll need to completely remove the little fin plate in the fin box that you used for your previous fin, and slide in the Wavegrinder fin plate. If you're at the beach, you'll have to find a couple little sticks to get your fin plate out of the box. The other downside to the installation is the screw is a Phillips head. It's the first time, we'd ever seen a Phillips head screw on a fin, so we had to go hunt down a Phillips screwdriver to install the fin. We were a little nervous about stripping the screw while we were tightening it up, but we had the right size, so it worked out fine. Once installed, the fin fit snugly in the box and we didn't have to sand nor shim the fin for a good fit.
Upon installing the fin, we learned that the fin has quit a bit of flex to it. We originally thought it would be somewhat rigid; however we would definitely classify this fin as a moderate flex-fin. Although we were taking the fin into small-medium surf, the flex in the fin had us questioning the integrity of the fin in larger surf. The fin is guaranteed against breakage for 60 days from the date of purchase. The site says that Wavegrinder reserves the right to repair or replace the fins with shipping to be paid by the customer. Once installed, the fin seems to flex a bit more when bent to one side over the other. In other words, it has slightly more flex to one side. It wasn't pronounced to the point that we were concerned since waves are organic by nature anyway.
In the Surf - Pros
Natural: It was a pleasant surprise how natural the fin felt from the first wave in the water. Normally, new fins take some time to get accustomed to, however, this fin felt natural and controlled from the start.
Turning: The fin responds well for both drawn out lines and short cutbacks. It is rare that a fin performs in such a dynamic range. Keep in mind, again, this testing was done in waist to shoulder high surf.
Takeoff: Wave take-offs were stable and controlled. The fin seems to eliminate some of the jolting and skidding that tends to take place on take-offs. Even whitewater takeoffs were surprisingly stable and controlled.
Glide: In flat water, it was hard to tell how the fin affected the glide of the board, On the wave, it seemed to carry the board through sections that normally would not be made. In fact, one surfer said he had to look behind at the tail of the board because he was still moving with speed on a smaller non-breaking section of a wave that he didn’t' think should have the push to keep him going.
In the Surf - Cons
Release: Although the fin allows for burying the rail and strong cutbacks, the fin didn't seem to release off the top. It seems only logical that this would be the case with the winglets. So, if your normal arsenal of surfing maneuvers requires some fin release off the lip of the wave, you'll be limited by this fin. There is still enough drive to throw water and hit the lip, however, you won't get the release and or slide that you would get with either a thruster or more traditional fin.
Fluidity: For some it's a pro, for others it's a con. As was mentioned previously, the fin makes the board stable and controlled. If you enjoy playing off the chop of the imperfections of a wave, this fin will take you through those instead of driving off of them.
In the Surf - Unknowns
Down the Line Speed: We did take the board down the line on a couple waves but the surf wasn't big enough to draw a definite conclusion. The walls we took the fin down the line on were just curling over at about shoulder height. Normal speed was maintained, the fin held its line, however, there wasn't the acceleration that is normally felt in such a scenario. Again, we feel that we'd need to test the fin in a bigger wave to draw a definite conclusion in this respect.
Nose riding: Given the board we were testing the fin on, nose riding was not part of our testing on the demo day. We've been told by third parties that the fin makes for excellent nose rides. Given the added stability, we have no reason to doubt it. However, the added stability may be put in check by the increase in tail lift by the wings. Again, we weren't able to form a definitive review of the fin's effect on nose riding.
Summary: To wrap it all up, the Wavegrinder was a lot of fun on a stand up paddle surfboard. It felt natural and responsive in the surf, and also carried speed in the flat sections. Drawn out and tight turns were both strong and controlled. We'd recommend the fin to anyone looking for these characteristics in a fin. The only main drawback is the lack of release off the lip of the wave. We have questions about the integrity of the fin in larger surf. If we ever get the opportunity to try the fin again when the surf comes up, we'll complete the review in that area.
For customer service, we recommend going to your local retailer. Over the last year, we have sent multiple emails to Wavegrinder for additional info, all of which have gone unanswered. They have a 60 day warranty on the fin, which isn't much, and if you get a defective product covered under the warranty, you'll have to pay the shipping to get it replaced, which is ridiculous in our opinion. To order the fin from the company direct will cost you $65.00 plus $12.35 shipping, plus, tax if you're in California. We recommend picking yours up from a retailer near you. Hawaiian South Shore (www.hawaiiansouthshore.com ) carries them on Oahu and retails them for $78.
Stand up paddlers and longboarders in general, think highly of the fin. Our local retailer is almost always sold out. The last guy that demoed one decided to leave the fin on his board and just buy the demo. If you have the opportunity, it's worth the time to swap out your fin and give it a try. In fact, there's a stand up paddle surf contest coming up and one of us may ride it in the event. Now that the review is done, we're going to check out all the technical stuff on the website www.wavegrinder.com .