You might have noticed that many surfers have fins installed on their surfboard. Why did they do that, is it just to look cool? Or does it actually serve a practical purpose?
Consider this. Why do sharks, whales, or any other types of fish big and small have fins? If they were useless, natural selection would have made sure that fish with fins died out. Clearly fish with fins survived due to the advantages they provide, hence why surfers have since copied the “design” of fish by putting fins on our surfboards.
What do fins do for us? In the same way that a rudder helps a boat, surf fins make a big difference in terms of stability, control, speed, and responsiveness. Don’t underestimate what these small hydrofoils can do for you. These fins will drastically improve your surfing performance once you’ve passed the novice level.
With fins, you will “slice” through the water in a way that a finless board can’t do. There are also many types of fin set-ups, and they each have their pros and cons. In this article, we will analyze these different fin set-ups and see what conditions they excel in. You’ll learn just how big of a difference having surfboard fins will make on your performance.
Why use surfboard fins?
Surf fins have a major impact on your performance. Once you’ve surfed with fins, you won’t want to go back.
Without the right fins for your surfboard, surf style, as well as surf conditions, you’ll experience constant slipping and sliding along the wave with no hold at all. You’ll also struggle to turn at a steep enough angle to surf along the face of a steep curling tube.
It’s hard to know what you’re missing out on if your only experience with surfing is on a finless board. However, some surfers claim the difference is like night and day.
Keep in mind, surfboard fins are beneficial, but they are NOT essential. Some surfers enjoy the odd session without fins to experience the sliding feeling again. Sometimes you should force yourself to feel some hardships so that you can treasure what you have, or something like that.
However, there is a reason why all correct surfboard setups have fins.
What do fins on a surfboard do?
There are two primary reasons to have surfboard fins: stability and control.
Even though there are many fin types, setups, and angles that have their advantages (which we will cover in their own section), they all serve to give you more stability and control.
Without fins, you’ll be slipping and sliding along the surface of the water. Fins will give you more “hold” so that this stops happening.
Due to the angle and direction of your fins, water will travel around them and push on both the interior and exterior of the fin, “holding” it in place.
The closer the fin is located towards the stringer, as well as the larger and straighter the fins are, then the more hold your surfboard will have. However, this setup is less responsive to turns.
On finless boards, or boards where the fins are too small for the board or the swell, you will feel like the tail of your board is constantly sliding out.
Just as a boat’s rudder assists in turning, so do the fins on your board.
When you put pressure on one side of your surfboard, you adjust the angle at which water travels around the fins. This is similar to skating on a longboard or snowboarding.
Set-ups without center fins or with fins towards the rail of your board have the quickest reaction times but don’t have as much hold as larger, centered fins.
Without the proper fins, or if set up incorrectly, you can actually make it harder to turn with your surfboard since there will be no surface to push against to adjust your angle.
Types of surfboard fins and what they do
In this section, we will cover the four most popular fins and how they are set up. We discuss their advantages, disadvantages, and the optimal conditions to use them in. Keep in mind, these are not the only surfboard fins, just the most popular.
Single fins are typically found on longboards. This fin setup is considered outdated by some, but it’s a classic that many still appreciate because it’s cool to experience what many old-school surfers used to ride with. Single fins are wide, long, and big enough to control the surfboard on its own.
They are best used in small to medium surf, with fat but weak waves. Their main advantage is that they provide good speed, because the fewer fins there are the less drag there will be. Single fins allow for smooth, slow turns, and can prevent spinning out in the tube.
However, single fins are not good with fast, sharp turns. If you’re used to surfing with multiple fins, you will feel like you have less stability. They are usually the largest fin, with some reaching lengths of 25”.
Twin fins are yet another old-school fin setup which was popularized in the 70s and early 80s. Surfing legend Mark Richards showed the whole world how effective it is by winning four consecutive World Championships.
What is so good about a twin fin setup that gave him that advantage? For one, it’s more stable than a single fin. As Richards’ competitors quickly found out, the twin fin also provides more maneuverability and speed than a single fin setup. This is thanks to the lack of a large center fin and limited rail fins.
That said, twin fins can feel loose as surfers found the tail would sometimes slide on bigger waves. Also, since the fins are toward the rail and small, bottom turns are more difficult because the board does not have as much hold compared to single fin and three fin setups. Thus, it’s ideally used in small to medium surf.
Thruster fin (three-fin setup)
Finally, we move onto the most popular modern fin setup, and it is useful whether you’re a beginner or a pro.
As much as the twin fin was a step up from the single fin, it was still frustrating to deal with its lack of hold in bigger waves.
That was when Australian Simon Anderson came up with the idea of the thruster fin in 1980. By placing an extra fin in the middle at the back of the tail on a twin fin setup, the thruster fin setup gave surfers the extra stability and maneuverability they wanted from a twin fin setup.
Since then, the thruster has played a pivotal role in the growth of high performance surfing, making it possible to reliably perform more radical maneuvers compared to before. It has an even balance of responsiveness, speed, and good hold.
With a thruster fin, you can surf in nearly every condition, from calm to epic waves. The third fin makes the board hold well in powerful, steep surf and tubes.
However, with each extra fin added the drag increases, slowing you down. It’s a small price to pay for the incredible maneuverability and stability it provides compared to the previous two fins.
Overall, thruster fins are a good middle-ground between what the single fin and twin fin setup offers.
If you can guess what’s coming up next, the quad fin adds yet another fin to the surfboard, so now we have four fins. The quad fin setup gets some of the benefits of both the twin fin and thruster setup.
Quads are great in small surf, particularly if the rear fins are located closer to the rails and further up on the surfboard. The way the fins are set up, water is channeled through the center and tail of your surfboard, allowing for a fast, loose, and responsible setup.
This lets surfers generate speed, even in weak waves, and makes it easier to do quick turns like how a twin fin would but with even more control. However, this makes it harder to surf on choppy water.
By placing the back fins further back on the board, surfers can also use quads in big hollow waves because of the extra hold it provides. Experienced surfers like the extra speed boost from not having a fin in the center as well as the increased hold on higher lines thanks to the two fins near the rails.
The quad fin setup can be used in numerous conditions as well, but it’s at its best in clean, powerful surf.
Other fin characteristics to consider
As important as the fin setup is (i.e. the number of fins and their location), it’s not the be-all end-all. There are other factors to consider, such as the fin size, flexibility, length, and so on.
First, let’s start with fin size. The bigger your surfboard fins are, the more surface area is in contact with the water, giving you more hold. Smaller fins give you less hold, creating a looser feel.
Next is fin flexibility. This is how much movement a fin makes from side to side. The stiffer a fin is, the less flex it will have. Ultimately, the fins will release quicker, helping you achieve quicker turns, but you will have less drive. Conversely, more flexible fins take longer to reach maximum flex, take longer to release, but have greater drive.
There is also the fin base to consider. The fin base is how long the fin is at the part where it meets the board. Longer bases give more drive. When a surfer turns, the fin flexes, creating pressure against them and creating acceleration. Small fin bases provide less drive but allow for quicker turns.
Moving on, we have the fin rake or sweep. A fin rake refers to how far the fin tilts backwards. Fins with less rake can turn and pivot quickly. Longer rakes create slower, more drawn out turns. Generally, more fin sweep is enjoyable on big shoulders.
These are just a few of the main fin characteristics to keep in mind. We’ll leave off with one more factor to consider: the shape of your surfboard’s tail. Together, the fins and the surfboard’s tail shape should work in harmony to provide the surfer with increased control in the water.
Do surfboard fins float?
Surfboard fins are costly, and losing one is a pain in the butt not just because of how important they are to the performance of your surfboard, but because they are expensive to replace.
Thus, one question we will preemptively answer is whether they float or not. If they float, then there is a chance that you (or another surfer) can retrieve it before it’s swallowed up by the ocean.
Some surfboard fins do not float, whereas some do. You will have to test yourself if your set of fins float in the water.
However, even if your fins do float, it’s not a guarantee that you can retrieve it. You can increase your odds of spotting it by getting brightly colored fins. Retrieving it is another issue.
They say that prevention is the best cure to a problem, so before worrying about all of these factors, focus on securing it properly onto your surfboard. If they never come off in the first place, then there’s no problem.
Do all fins fit all surfboards?
Unfortunately, surfboard fins are not universal. Before purchasing the fins, make sure that the fin base is compatible with the fin box system on your board.
To sum it up, surf fins play an important role as part of a functional surfboard setup. To answer the main question, they do, in fact, make a big difference on a surfboard.
Without surfboard fins, you will have little control over the surfboard as it slides all over the place. You will feel a lack of control, find it hard to turn, and have less balance than a surfboard with fins.
There are many types of fins and fin placements which we call the fin setup. You can have different setups depending on the swell, surfboard size, and your surfing experience. You can adjust the fin setup to give you more stability, turning capabilities, speed, and overall control.
Surf fins are not strictly necessary in order to surf, however once you’ve surfed with one it’s hard to go back. Unfortunately, they are not cheap pieces of equipment. If you plan on surfing for the long term, they are probably something you’ll have to invest in at some point to get the most of your surfing experience.