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Sup & Surfboard Fin Technology - FinSciences

Surf & SUP Fin Technology


4.8″ FinSciences FSI fins as sidebites in a 2 + 1 setup with a WG2

Fin Sciences is about Surf & SUP Fin Technology. We make fins that make surfing and paddling more fun. We get rid of excess drag—and that translates to more drive, easier paddling, better acceleration, more speed, better turning, and longer surf and paddling sessions! Read more about why.

New small shortboard fins in a thruster setup

New small shortboard fins in a thruster setup

We ignored surfboard-fin folklore and tradition in designing our fins.  We started with a clean slate, and used solid, modern science to create fins that are unique, so unique that they’re patented.

You’ve probably seen some of the features we use in our fins, like winglets, used elsewhere these days. If you’ve ridden an airplane recently, probably you’ve noticed winglets on the end of the plane’s wings. Winglets are there because they reduce drag—and they reduce it a lot. NASA and Boeing scientists found that winglets reduce wing drag by 20 to 30 percent. Read article. Sailors know boat keels with winglets help boats perform better and win races.

Our fins produce a lot of hold and drive with less surface area, so you get better performance using a smaller fin than you usually use—smaller by about 20 to 30 percent. A smaller fin means less skin-friction drag, because every square inch of fin you drag around under your board creates drag. Less drag means easier paddling, more speed, and longer sessions. Read more about how to pick the right size SUP fin. Our fins make surfing more fun too—you’ve got more drive through crappy wave sections or conditions, less stalling during cutbacks and bottom turns, and easier acceleration for better wave-catching ability. Easier paddling means longer sessions.

FSI fin-tip flow shown in CFD image

FSI fin-tip flow

Our fins have a high-aspect ratio to reduce drag and increase lift—hold and drive. (Read more about lift, drag, hold and drive.) We use a foil section that inhibits stalling. Our fins also reduce drag with a bulbous forefoot (like on airplane tails) and a cutaway too.

The science of all this is proven. We didn’t just adapt an existing fin design, or paint graphics on the usual dolphin fin and call it new. We started with a blank slate. We studied and researched advanced foil, fin, and wing design, aerodynamics, hydrodynamics, fluid dynamics, and physics. Then we tested some of the most advanced foil sections available. We combined a bunch of scientifically proven features in one fin design to make these fins go fast and turn well. Sure, you can surf with drag. We used to fly kites way back when with rags attached to the tails to keep the kite up and into the wind. They flew. But grandpa’s kites of the 1960s aren’t nearly as maneuverable as modern-day kites.

WG2 in translucent blue

WG2 in translucent blue

Dolphin dorsal fins look just the way they did generations ago. Over time, hydrodynamic science has evolved. Why haven’t fins? Why do traditional dolphin fins take the center fin like on a dolphin’s back and stick it on the tail of a surfboard? Why do we use two dolphin fins—like in a thruster setup, where one is a double foil (symmetrical) and the other is chopped in half, with one asymmetrical fin on each side of the board?

SUP racers and SUP race-board companies are increasingly looking to naval architects to design low-drag race paddleboards—to squeeze out even a few seconds of paddling time. In a half-hour SUP race, even a one percent difference in time paddling could be as little as 18 seconds. Fins with less drag allow paddling fast, winning SUP races, and having fun.

First we created the Wavegrinder fin for longboards and SUPs. Then we added shortboard fins to our line-up. We’re working on new SUP fins for downwind and straight-line speed, with kelp- and weed-shedding features too. Fin Sciences’ fins are different. We don’t try to be the last word on all this—we want to be part of the discussion. We encourage surfers and paddlers to try FSI fins against their favorite fins, and join the conversation.

We hope you’ll give our fins a try—even though they don’t look like your granddaddy’s fins!

What People Say

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!



I’m so glad you are getting this fin to market because I have ridden them and I really believe in them. To me they are the future of surfboard fins and I tell everyone that will listen that eventually everybody will move across to fins like this. To put it simply, the fins work so much better than regular fins.



Hey!! Just tried it out on my Stand Up Paddleboard. 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 Paddleboard is 11 feet by 30 inches and now spins a 180 with one stroke…

Sincerely, Sandy.


Just wanted to let you know that the day I received my new Wavegrinder longboard fin I fitted it on 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 previously and I got to the nose better than before. What a blast of fun.



I bought a wg2 for my 9’2″ longboard and I love it.  Thx for the science.


The WG2 fin is awesome, I’ll never ride a traditional raked fin in my single fin longboards again, as when I retried my regular set up, the board felt drunk in comparison.

Jeff R

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! For surfing Costa Rica, the Dominican Republic and at home I will certainly be surfing the Wavegrinder.


I just want to give you some feedback. I’m 6’1” 210 pounds. I prefer to ride shortboards but when the surf gets small or during the winter I will ride my longboards. When I do ride them I tend to ride them more like a shortboard. 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 good, so I have been riding my shortboards. A couple weeks ago I went down to Hatteras, NC, for a little vacation and had good surf all week. The swell did drop toward the middle of the week, so I pulled out my longboard 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 loved it. He was getting sick rides. He said he wanted to borrow 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 can say I have had maybe 4 surfs in the last 2.5 years on regular fins and each time I feel like the dolphin fins are just so slow by comparison.


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.


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.  We are spreading the word so hopefully you will get more orders. By 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. My brother kept throwing himself off his board it was so quick!

Thanks for a great invention.

Tom Blake would be proud.


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. Steady while 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.


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.


firstly, i’m a huge proponent of your fins. as a fan of physics, i enjoy understanding the design elements used and share that info whenever i engage other surfers who ask about the fin when they see it.

i ride a rick rock 9’6” rounded-pin with your semi-flex fin. it rides very predictably and doesn’t cavitate on harder bottom turns. it accelerates quickly, pivot- and carve-turns confidently and holds great while nose-riding.

thanks for making great fins!



In small waves, I was surprised by how my board ( 9′ Surftec, epoxy, Takayama) snapped off the top, and there was even some speed left to do the bottom turn. Yesterday I got it in head-high at Torrey Pines. The board seemed faster down the line, the snaps off the top and bottom were no problem.


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 its claims, but the Wavegrinder exceeds by 100%. You’ve increased my stoke considerably, which I didn’t think was possible. I wish you much well-deserved success. thx


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 wave the board would pick up speed faster than 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!


Hello Doug,

Am still using your fins [longboard kiteboarding] with great results. I always talk them up here in bustling Cleveland and around the Great Lakes.

I hope this finds you well.


Got a Question? Contact us.

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