Superior Performance = More Fun!


You know how sometimes your board seems sluggish, hard to paddle, and slow to turn—it’s not performing like it used to? FinSciences modern surfboard fin and SUP fin designs amp up the energy in your board by reducing drag and increasing lift (hold and tracking) so you can have more fun on the water—and for a lot less money than a new board! We design our fins based on solid science, not tradition and folklore.

FinSciences 4.8″ fin


Total area: 10.14 in²
Template/planform area: 9.75 in²
Finlets area alone: 0.9 in²
Height/depth: 4.8 in
Rake/sweepback: 22°
Foil section: symmetrical (double)
Anti-cavitation trailing edge
Stiffness: semi-flex or stiff
Colors: gloss black, blue, matte black
Fits FCS (and Futures with adapter)


(1 customer review)

FinSciences 5.7″ fin


Total area: 14.6 in²
Template/planform area: 13.6 in²
Finlets area: 1.1 in²
Height/depth: 5.7 in
Rake/sweepback: 22°
Foil section: symmetrical (double)
Anti-cavitation trailing edge
Stiffness: semi-flex or stiff
Colors: gloss black, blue, matte black
Fits FCS (and Futures with adapter)


FinSciences 9¼” fin


Total area: 30.6 in²
Template/planform area: 29.1 in²
Finlets area: 1.5 in²
Height/depth: 9.25 in²
Rake/sweepback: 15°
Anti-cavitation trailing edge
Stiffness: Semi-flex or stiff
Colors: Gloss black, orange, blue, clear, or matte black
Fits Fins Unlimited and Bahne fin boxes




FinSciences makes modern surfboard fin and SUP fin designs. Our fin designs are based on solid science, not tradition and folklore. So they look different from traditional fins. Read more about surfboard fin science.  Here are some of the key features of our fins.

Modern Surfboard Fin and SUP Fin Designs 1


Finlets help maximize the use of all our fins’ surface area. Finlets work by preventing the flow of water around the tip of the fin, which robs typical fins of their efficiency and power. Most fins make up for inefficiency by adding more surface area.  But that adds drag and slows the fin.
Modern Surfboard Fin and SUP Fin Designs 2


With a short fin base (about 4″), there’s lots of room to adjust FinSciences longboard/SUP fins forward and back in the box to dial in your ride. Longer-based fins can’t move as far forward or back in a fin box.
Modern Surfboard Fin and SUP Fin Designs 3

Small surface area

Our fins create the same hold/drive/tracking as other fins but with about 20-to-30 percent less area. This is a key takeaway about why our fins work so well—they’re fast, and accelerate easily given their small area (less skin-friction drag) but still have lots of power for turning and tracking.
Modern Surfboard Fin and SUP Fin Designs 4


The cutaway helps reduce interference drag at the board-fin intersection.  Cutaways need not be large as many believe; the objective is to reduce the length of the fin base and fin area in the boundary-layer area where the fin intersects the board,
Modern Surfboard Fin and SUP Fin Designs 5

Forward-projected base

Like the bulbous bow of a ship, the keel of sailboats and and the forward-projected base of many airplane wings, tails, and rudders, this forward-projected fin base reduces interference drag at the boundary layer of flow where the fin intersects the board.
Modern Surfboard Fin and SUP Fin Designs 6

Low-sweepback/rake angle

Our fins’ low sweepback angle—low rake angle—helps prevent stalling, which is a loss of lift on one side of the fin as occurs when dropping in, and making cutbacks.
Modern Surfboard Fin and SUP Fin Designs 7

High-lift, low-drag foil shape

The foil shape—the cross-sectional shape—that we use maintains lift/hold/drive without stalling over a wide range of angles of attack, as when dropping in or making sharp cutbacks.  We didn’t just pick a foil at random or hand-shape it in the garage, we used solid science in making the foil selection.
Modern Surfboard Fin and SUP Fin Designs 8

Symmetric, double-sided foil

Our fins are symmetric or double-sided foils for excellent lift/drive/hold without stalling over a wide range of angles of attack, as when turning and making sharp cutbacks.  Typical asymmetric, flat-sided fins work well in one direction, but stall in the other.
Modern Surfboard Fin and SUP Fin Designs 9

Oblique Trailing Edge

Our fins feature an oblique, Von Karman trailing edge to reduce oscillation drag.  Trailing edge vortices occur at the edge of rounded and flat trailing edges and create drag, so we use a Von Karman edge to inhibit trailing-edge vortices and reduce drag.
Modern Surfboard Fin and SUP Fin Designs 10

High Aspect Ratio

Our fins are tall and narrow for low drag and high lift/hold/drive.  Shorter, squatter shapes as is typical in dolphin-fin shapes have more drag and less lift per square inch.  Our fins resemble the high-aspect-ratio shapes of commercial aircraft wings, tails, and rudders—and not typical dolphin fins—because high-aspect shapes are better.
Modern Surfboard Fin and SUP Fin Designs 11

Low taper ratio

Our fins are pretty rectangular—like on this F-14’s unswept wings—because that low-taper-ratio design creates more lift per unit of drag than more more triangular shapes. Low taper ratio = more rectangular.  Higher taper ratios, common in dolphin-shaped surfboard fins, increases downwash and decreases efficiency.
Modern Surfboard Fin and SUP Fin Designs 12

Details, details.

We have a variety of other details in our fins.  The tip has the same shape as the foil’s cross-section.  The material we’ve chosen is the material used in bulletproof glass, jet-fighter canopies, car headlights, boat portlights, and safety glasses.  The screw we use is a number 6 truss-head screw.  The metal parts are marine-grade stainless steel; not just any stainless.


FinSciences fins are designed to be fast, yet with plenty of hold and drive so you can get some air and have more fun!

We don’t just say “faster, with more hold and drive;” we compute it. We use CAD and CFD design programs and principles to design fast fins with plenty of power.

Our whole idea is to do more with less.  We use science to design fins with more hold and drive, and less drag than typical fins.  Yeah, everybody talks about more hold and drive, but we actually used  numbers and science to amp up our fins’ hold and drive. The result: our fins are easy to paddle, accelerate, track well, and turn without stalling for more fun on the water—or in the air!

Modern Surfboard Fin and SUP Fin Designs 13
Modern Surfboard Fin and SUP Fin Designs 14
Modern Surfboard Fin and SUP Fin Designs 15


FinSciences fins take less horsepower to paddleLess-tired arms, more speed, and more fun!

We designd our fins to move through the water easily with low-drag shapes that still offer great stability and tracking. Out WG2 9¼” fin takes .0045 horsepower to paddle at 5 knots.  We also have numberss for lift/hold/drive/side force generated at various speeds, which translates to tracking ability, as well as numbers for the amount of drag at various speeds, and the lift-to-drag ratio—all these numbers have gone into our fins’ designs. They aren’t just art or something we whipped up in the back of the garage, we used CAD and CFD fluid-flow design principles and programs in creating our fins.
Modern Surfboard Fin and SUP Fin Designs 16
Modern Surfboard Fin and SUP Fin Designs 17
Modern Surfboard Fin and SUP Fin Designs 18


When’s the last time you wrote a company to tell them how much you loved the product? Here’s what some of our customers have had to say—unedited.

I just want to give you some feed back. I’m 6’1” 210 pounds. I prefer to ride short boards but when the surf gets small or during the winter I will ride my long boards. When I do ride them I tend to ride them more like a short board. I like performance surfing. I read your ad and decided to give it a try. I have had the wavegrinder for a few months and I love it. I have it in a 9’1” McTavish Original. I rode it with two FCS h2 side fins. I could immediately tell the difference in the performance. Then I ran up to the nose and got the longest nose ride of my life. Well the water started to warm up and the surf has been goods I have been riding my short boards. A couple weeks ago I went down to Hatteras, NC for a little vacation had good surf all week. The swell did drop toward the middle of the week so I pulled out my long board and was getting some good rides. My buddy has never seen the wavegrinder before and I was telling him about it. He asked if he could try my board and he love it. He was getting sick rides. He said he wanted to barrow my board for a contest. I told him it’s not the board, it’s the fin. He didn’t want to give the board back. I gave him your web page and he said he was going to order one. I’m getting this one for a 9’6” Hamilton. Can’t wait.

I loved the fin in the single fin shortboard. I tried it in a bonzer 5 setup, and single fin gun, a couple of different longboards, and a single fin shortboard. It worked far and away the best in the single fin shortboard, and very good in the bonzer too.

I recently replaced the fin on my 9 footer with the Wavegrinder Fin and took the board out for a test at San Onofre. The fin worked great all around on a 1-4 foot surf with glassy conditions all day. The first sensation I experienced is the board paddled exceptionally fast in fact I was surprised how fast I got out through the inside surf. Catching the wave was much quicker the board gained momentum with each stroke definitely a plus when there is a crowd. Once I was on the wavethe board would pick up speed faster then my regular fin and I could turn the board in a tighter radius, a pivot type turn with no loss of speed. The glide was great and nose riding was smooth and effortless and cutbacks were also smooth. The straight line speed had drive which amazed me for a fin with a narrow base. I can’t wait to get the fin out in overhead surf.

Thanks Again,


Well I finally got some decent surf in which to try your fin.


It screams out of turns just as you promised, I just may have to get a few more…. I promised to send photos of my work, so enclosed you should find a few. Thanks again for your fin, it brings yet more fun to my surf!


P. M.


Just wanted to let you know that the day I received my new Wavegrinder longboard fin I fitted it my board at lunchtime ready for a quick dash down for a surf after work. Beautiful little point breaking waves. Oh boy, what fun. I exhausted myself very early in the session. Hadn’t caught so many waves in such a short amount of time before. The fin seemed to allow me to paddle onto the waves much easier, the board felt more loose than previous and I got to the nose better than before. What a blast of fun.




Just wanted to give you some positive feedback regarding the Wavegrinder fin. I’ve been surfing it for a few weeks now and am completely stoked. First time out, I was most impressed by the projection out of bottom turns and the sensation of feeling the fin flying thru the water. Per the recommendation I had the fin a few inches back than normal for me. The next time out I moved it up about an inch and a half to see the difference. Didn’t work nearly as well. Interesting that the placement makes such a difference. Very seldom does any new product or innovation live up to claims, but the grinder exceeds by 100%. You’ve increased my stoke considerably, which I didn’t think was possible. I wish you much well deserved success. thx



Your longboard fin is amazing!


While waiting for my new board to arrive, I ordered a Wavegrinder. After having ridden the new board with the 2 +1 fins sent with it, I switched to the Wavegrinder and went out in 5′ to 7′ surf. I was surprised how much easier paddling out was and how much faster the board seemed. Your fin performed just as advertised. I’m going to order another for my noserider.
T. A.

Had my first surf today using a Wavegrinder Fin. Absolutely awesome! I caught more waves in one session than I have had my last 3 sessions. It is far easier to catch waves with, much faster in a straight line and way faster coming out of turns. Every longboarder on Earth should have one of these fins. If your old mal is getting a bit stale, breathe some new life in to it with a Wavegrinder! Way cheaper than a new board – a blue chip investment. I loaned my board to a 60 year old mal rider and after two waves he was sold. Couldn’t wait to hand over his money to me in the car park!


The fins are AMAZING so much speed out of a turn and paddling couldn’t be easier my brother and I are very impressed. I’ve been out several times this week and I couldn’t be happier, today was a little steep but the fin put me in quicker so I was down the line before the wave could get me.All the short borders hate me, they want to know if you are making a fin for the short board.We are spreading the word so hopefully you will get more orders. Bye the way the turning is so quick we had to put the fin 3/4 of the way towards the back of the fin box, with the fin in the same spot as the turbo tunnel my brother kept throwing himself off his board it was so quick

Thanks for a great invention.

Tom Blake would be proud.


Hey!! Just tried it out on my Stand up paddle board. Amazing!! Thank you. What a difference. #1 the board tracks better. # 2 Hauls ASS! # 3 turns on a dime # 4 seems to lift my nose up when I’m doing long powerful paddle strokes to get better speed # 5 Board seems more stable…

All hard to believe, but I totally noticed the difference immediately.

My stand up paddle board is 11 feet by 30 inches and now spins a 180 with one stroke…




I Like it!!! Played in some 3-4’ stuff in HB this past weekend and had great fun. Allowed me to get that 10-0 around pretty quickly. Pretty steady at the nose too.

I had it moved about two inches behind where I usually place the other fins.

Good fun…..I look forward to better waves with it.


Dear Sirs,

I gave that Wavegrinder fin a real workout in Baja over the weekend and had a lot of fun with it. We had consistent glassy surf for three days that ranged between 4’ and 10’. As an old traditionalist it was quite different trying something that new and I found it to be everything you said and more. My turns were very smooth and the transitions from a cutback to a bottom turn were fast and I didn’t notice any stalling, obviously I really liked it! HOWEVER, kelp is not a good thing for a vertical fin. For surfing Costa Rica, the Dominican Republic and at home I will certainly be surfing the Wavegrinder.




Thank you very much for the extra plates and screws. I’ve surfed the fin 4 times, the first 3 times it was mostly small. I was surprised by how my board 9′ surtec, expoxy, Takayama, snapped off the top, and there was some speed to the bottom turn. Yesterday I got it in head-high Torrey Pines. The board seemed faster down the line, the snaps off the top and bottom were no problem. We talked about how tight it was in the box, and I remember you telling me to have the fin in the back of the box. I’m gonna sand it down and move it back. the board has alota tail rocker and I’m interested to see how it works out. Thanks again. P.


Modern Surfboard Fin and SUP Fin Designs 19


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