SUP Fins Set-Ups and Fin Box Types Explained

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You will find a good amount of articles out there that talk about SUP fins and their setups. Unfortunately, this advice is less than prevalent to 80% of paddle boarders because it comes from a surfing angle. 

This article comes from an inflatable paddle board background and will mostly be touching on fin-setups for a variety of different paddling conditions.

So while yes it would be nice to have that really cool-looking carbon honeycomb fin. The reality of the situation is that it will likely be overkill in most scenarios with an inflatable SUP. 

In this article we go through everything there needs to be known about fins and how they work together with your inflatable paddleboard. We will also touch upon definitions and which set-up is best for your needs. 

Let’s get into it!

What Do The Fins on a SUP Do? 

Paddle Board fins allow you to paddle forward in a straight line. This in turn will give you more control over the board. If you paddled without the fins, the board would not be able to move forward (or track) in a straight line. But rather the SUP’s tail would move from side to side also known as “fishtailing”. This in turn makes it more difficult to keep the board in a straight line when paddling. 

There is always a battle of give and take that you need to consider with paddle board fins regarding speed, tracking, maneuverability, and stability. So in this case it’s always best to figure out how experienced a paddler you are and what environment you are paddling in. We will go through this in more detail below. 

Truth be told, fins do not make as big of a difference to your paddling as they would when surfing. This is because of the slower speed you are traveling. The best way to improve your paddling skill set is to work on yourself and the efficiency of your paddle stroke. 

As you get more experienced in paddle boarding you will feel more and more of a difference between different fin setups. 

Isle did an interesting test on how different paddle board fins affect the board’s performance which you can read about here. 

Understanding Fin Anatomy

Before understanding which fins are best for what types of environments it’s best to understand the physics behind their anatomy and how it affects the fin’s performance. 

Fin Base: The base is the section of the fin that gets installed on your board. The areas of performance that this fin affects is stability and tracking. The thinner the base the less stability and tracking you will get. Conversely, you will get more maneuverability as a result. 

Fin Tip: The tip is the furthest point away from the base. This part affects the speed and tracking of the board. The longer the fin tip the better it tracks. But in doing that you also lose speed. The tip also aids in stability. The longer the fin, the more stable your board will feel in the water. 

Leading Edge: This is the front part of the fin that runs into the water first. The main segment that this affects is maneuverability. The smaller the leading edge is the more maneuverable your board will be. 

Trailing Edge: This is the backside of the fin that, like the leaning edge, affects how well the board maneuvers in the water. The less trailing edge the fin has the more maneuverability you will have. Folks who do pivot turns often look for boards that have less of a trailing edge. 

Flex: Flex refers to the stiffness of the fin. Many paddleboard manufacturers have flex fins made of a softer type of plastic. This allows them to absorb the impact that they may take from things that lurk below. In contrast, stiffer fins give you more control and give you better tracking. Softer fins give you better maneuverability because of their bend but will not offer as much tracking ability. 

Rake: Also known as sweep, Refers to how far back the fin curves and the amount of curvature the fin has at the backside. The more rake a fin has the better it will track and the more stable the board will be. But this comes at the price of maneuverability.  

A real-life example of this would be that a racing fin that has a more square profile provides better tracking because it has more rake. Compare that to say a river fin which is smaller and has more curvature which provides better maneuverability. 

Fin Box Types

Now that I have you all curious about how fins can change the behavior of board. Let’s talk about fin boxes. Before you go about buying a racing fin from Amazon or your local SUP shop you have to know what type of fin box your SUP supports!

Slide In

Slide-in fin boxes are more prominent in cheaper ISUPs that you find on Amazon or big box retailers. They sometimes can be found on entry-level SUPs like the Bote Breeze and as well as ROC, Dama, and Funwater

These fin boxes are usually made of plastic and slide into place. They come with a plastic clip that secures the fin to the fin box. These fin boxes are lightweight but the cheapest made which limits you to plastic slide-in fins. 

When I first bought my entry-level SUP the board I bought had one of them. I never had any problems with it but hopping from that to an iRocker I could definitely feel some of the differences almost instantly in terms of handling and performance.” 

– Editors Notes

Universal Fin Boxes

These are the most versatile fin boxes and therefore my favorite of the three to use. The most common versions of these are the US Standard US Fin box for the center fins and FCS (Fin Control System) for the side fins. 

When I’m choosing a paddle board I always like to have options available to me, especially when it comes to fins. With Universal fin boxes, you can swap out the fin that comes with the board for any fin that has the US Standard or FCS fin box labeling. 

This allows you to tune your paddle board just right to your liking as well as to suit your environment. I’ll paint an example below:

If you bought a model of board that comes with a 9” dolphin fin but you are paddling in a shallow river environment. You would have to switch to a 4.5” flexible river fin to avoid scraping the bottom. With a US Standard Finbox, you can buy this fin from any 3rd party that sells compatible fins. With other fin systems like proprietary, you are at the mercy of the manufacturer’s prices and their availability. 

Brands that use Universal Fin Boxes include Red Paddle, StarBoard, Earth River SUP, Sea Gods, Nixy, Honu, Atoll, Isle Surf and SUP, and Naish to name a few. 

Proprietary Fin Systems

Proprietary fin systems are made to be manufacturer specific. Meaning if you want to purchase another fin it has to be from that specific manufacturer. This has some limitations as sometimes these fins are out of stock or even worse, obsolete to the boards you purchased years back. 

Oftentimes these paddle board companies use a “snap-lock” system in which the fin goes in 2 grooves in the fin box and locks in with a lever system. Most of the time this system does the job but you will find more customer complaints about missing fins due to a malfunctioning fin box due to heavy force applied to it or simply the lever coming loose. 

I’ve had this happen to a friend of mine where his iRocker All Around 11 board’s side fin got caught on the leash and ended up snapping off. Luckily he was able to order a spare no problem.

– Editors Notes

It should be noted that paddle board company has to pay a license fee every year to have an FCS/ US fin box designation so oftentimes proprietary fin boxes are a workaround for this. 

Paddle board companies that use proprietary fin systems include iRocker, Gili Sports, Thursosurf, and Bluefin

Permanently Attached Fin Systems

Many permanently attached fin systems are usually small side-bite fins that are attached to the board. Although there are some boards that have a thruster setup of permanently attached fins (all 3 fins are the same size).

These are probably some of my least favorite as the small side bite fins usually add very little in the way of tracking or stability because of their smaller size. They also take up a bit of extra room in the folding process which means that the board will not be as compact as it could be. This is even more true for boards that have a thruster set-up of permanently attached fins. 

Most Common Types of Fins for Inflatable SUPs

If you look online for fin information you will see all these different fancy types of fins made all the way from fiberglass to carbon to honeycomb. These are all very nice but unfortunately, they won’t be too helpful for your inflatable SUP in terms of performance. 

Below I will be talking about the most common types of fins that you will come across when you are looking for fins for your inflatable SUP. 

Center Fins

This is the most influential fin as it oftentimes is by far the more dominant in terms of size. It will also dictate the way your paddle board feels stability-wise, tracks, maneuvers, and how fast it can go. Below are some of the most common fins you will see for inflatable paddle board center fins. 

Dolphin Fins

These are by far the most common types of fins found on 90% of inflatable paddle boards when you first purchase them. Dolphin fins are great for all-around use as they give you good tracking without sacrificing too much maneuverability. 

The curvature of the fin gives you decent speed while allowing vegetation like seaweed to slide off. Dolphin fins can come in a variety of sizes from 4” all the way to 9”. Every single ISUP manufacturer will have these fins readily available

Touring Fin

These fins have the widest surface area of any of the fins as it has a square profile to them. As a result, they track the best but are also the least maneuverable, especially when it comes to quick pivot turns. These fins usually range from 8-10” in size and therefore will give you the most amount of drag due to their surface area. 

These fins will give you the most stability out of any of the other fins on our list. These fins can come in a wide array of materials from soft “flex” plastic to fiberglass and carbon materials. 

River Fins

River fins are like miniature dolphin fins. Oftentimes their size will be between 4-5” long. These fins are often flexible plastic that absorbs the impact from anything that lies below. This in turn protects the impact that the fin box may incur. 

These fins will give you more speed and maneuverability but less stability and tracking. This is all due to their smaller size. In fact, oftentimes these river fins will be smaller than the removable side fins that come with your inflatable SUP!

As the name suggests river fins are best used in river-like environments that have shallow water and more twists and turns

Speed Fins

Speed fins are lower profile fins that look like a shark fin. While these won’t give you the best tracking performance they will give you more speed and more maneuverability thanks to their shorter profile. These fins are also popular to use in SUP surfing conditions where you want a bit more aided maneuverability. 

Side Fins

For the most part, there are two types of side fins. The ones that are permanently on the board and fins that can detach from the board. 

Permanent Side Fins

In my testing and humble opinion, these really do not do much for you in the way of tracking or anything really. When I had my old board I tried taking the center fin off and just using the side bite fins. The board behaved like a bumper car. Lots of oversteer from side to side it was hard to paddle straight! 

These fins usually measure about 1.5 – 2” in length. 

The only advantage to having these on a board is the fact that you don’t have to worry about forgetting any fins. Companies that use permanent side fins include Atoll, Bluefin, Serenelife, Roc, Isle Surf and SUP as well as most Amazon, big box retail brands. 

Replaceable Side Fins

These are fins that you can take on and off of your board. The main advantage to these fins is that they help make your board more stable and track better in the water. These fins usually come in at about the 5” length although sometimes you can find some that are shorter or longer

“These are the types of side fins that I recommend as they make more of a difference to your board. Years ago when I was still using my old no-name board I was shocked at how much better my friend’s iRocker tracked. The boards were about the same length and similar shapes but the main difference was the addition of those 5” side fins!

– Editors Notes

Side fins will differ from manufacturer to manufacturer. Some Side fins will use a proprietary mechanism that allows them to snap in while others use an FCS (Fin Control System) that allows you to add side fins from 3rd parties. 

Boards that have replaceable side fins that come with the boards include Nixy, iRocker, Gili Sports and Thursosurf to name a few.  

Fin Set-ups for Inflatable Paddle Boards

For inflatable paddle boards you will usually find 4 different fin setups available to you. By far the most common will be the 2+1 fit setup though. 

Center fin Only

There are not too many all-around inflatable paddle boards these days that come with just this set-up. The ones that do usually come with a US standard fin box set up to give you some customization. The performance the fin can give the board will ultimately depend on the length and type of fin you choose. 

Center fin setups are more common on inflatable racing/ touring paddle boards. Models such as the StarBoard Zen series, Red Paddle Sport, Nixy Manhattan, and Naish Fusion boards

2+1 fin Setup

This is usually the most common set-up that you will see with all-around inflatable paddle boards. In my experience, this setup gives you the best tracking and stability. Especially if you have a 9” center fin combined with 5” side fins. 

These boards usually point straight as an arrow when paddling and offer more support when wind and waves come your way. 

This is also by far the most versatile set-up as you can choose between having a singular fin, just 2 side fins, or even a thruster (3 fins of equal length) setup! 

As mentioned above if you are interested in truly experimenting with fins I highly recommend you get a 2+1 fin setup where all the fins can detach. This will give you more fin possibilities to tune the board exactly to your liking and your surroundings. 

Most of the Best Inflatable Paddle Boards listed on this site have this set-up with replaceable or side bite fins. 

Twin Fin Setup

This setup can be referred to as 2 side fins or two center fins. The two-center fins setup is becoming more and more popular with ISUPs due to the rise of travel-friendly packages. 

Many ISUP manufacturers are now opting to go with 2 center fins because the fins can go on either side which allows the board to be folded up lengthwise

In my testing the differences between the twin center fin setup and the 2 +1 (9” center 5” side fins) are minimal. I did find that when paddling at a faster clip the two center fins had the advantage while the 2+1 setup was slightly better for casual paddling purposes in terms of tracking and stability. 

Boards that have the Twin fin setup include iRocker Ultra All Around 11, Cruiser, the Blackfin Ultra CX as well as the Nixy Huntington Ultra Compact, and the Red Paddle Compact series

Thruster Fin Set-up 

This is a setup that you don’t see too much on inflatable paddle boards anymore due to the fact that both the center and side fins remain attached. This makes the board harder to fold up and as a result, takes up more width wise. 

With this set-up what you have is pretty much what you get. No customization is available unless you take apart the board. Boards that have this design include the popular Body Glove Performer 11 board.

For a very detailed article on this check out Earth River SUP’s take on tuning your fin setup


Below are our most popular FAQs that we get about paddle board fins. 

Can You Paddle Board Without a Fin? 

Yes, you can paddle board without a fin, but your tracking performance as well as the stability of the board will be greatly hampered. It makes your board perform similarly to that of a bumper car.

I tried it for 10 minutes and immediately paddled back. Once you paddle with at least a center fin, there’s no going back!

What Fin Setup is Best for Touring?

Usually, inflatable paddle boarders use a single touring fin or a specialized speed fin for racing purposes to help with the stability and tracking of their boards. A lot of this is down to personal preference of the handling of your board and the type of racing/ touring environment it’s in. 

Blackprojectsup did an interesting fin comparison on the fins they sell in relation to SUP touring that you can read about here. 

What’s the Best Fin Set-up for Maneuverability?

If I’m in tighter waterways I personally like to combine a river fin with two side fins so that I still have some stability and tracking with a looser backend. If you are in deeper waters you can go with a speed fin setup as well that reduces the drag of your board. 

What Position Should my Center fin be in?

Some paddle boards like Atoll give you a US Fin box spec fin with an elongated fin box. This allows you to choose the position of your center fin to better customize its performance slightly. 

  • When the fin is farther forward it gives you more maneuverability 
  • When the fin is placed in the center it gives you the midpoint sweet spot between tracking and maneuverability. This is usually where I like to put the fin.
  • When the fin is placed further back it gives you better tracking and a straight line. 

What’s the ideal fin setup for Recreational paddling?

For the vast majority of folks who have inflatable paddle boards, a 2+1 replaceable fin setup is ideal. This setup gives you the best tracking starting out and gives you the option to try other fin setups down the road. 

For maximum flexibility look for boards that are US Fin box and FCS fin box compatible. This will give you the most options for fin experimentation down the line!

So How Should I Choose a Fin for My Paddle Board

The best way to choose a fin or fin set-up is to ask yourself the following questions.

  1. What Is my SUP Skill Level?
  2. Where Am I Paddling? Is it shallow? Will there be wind and waves? 
  3. What Factor is Most Important to You? Tracking? Stability? Speed? Maneuverability? 

If you are newer to paddle boarding it’s best to go for a 2+1 standard setup (9” dolphin fin with two 5” side fins). As you advance you can start experimenting with SUP fin setups that are more performance based like Speed fins, Racing fins and River fins. 

Where you paddle is an important factor as to what you choose for a SUP fin. The more shallow it is the smaller and more flexible your fins should be. Consequently, if there is more wind, waves and tracking/ stability is important to you, choose a longer center fin like a touring fin with two 5” fins as side fins. 

The last factor is more of a personal preference. If you are just starting out you will want a 2+1 fin setup with an 8 or 9” center fin to help with stability. As your skill level grows you can start purchasing smaller fins to work more on speed and maneuverability. 

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Hey, My name is Derek Lenze and I'm the owner of Inflatable SUP Authority. I've had over 20 years experience with watersports and over 10 years of various paddle boarding experience. My new-found passion is bringing my stand up paddle boaring knowledge in an explainable and actionable way all the while giving you my unbiased takes.

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