Paddleboards are relatively simple products but they do have some important components. Perhaps one of the most important components is the paddleboard fin. As you will see below, a fin is an integral aspect of the paddleboard and it helps movement through water and control. In this guide, we look at the replacement paddleboard fin, why you need one, and where you can buy one. We also provide a beginner’s guide to paddleboard fins for your benefit.
Paddleboard Fins Explained
First, let’s look at the paddleboard fin, what it does, and its design. It is entirely possible to use an SUP without a fin. However, the experience would be hard work, and you would find it incredibly difficult to direct your board and paddle efficiently.
What do paddleboard fins do?
A paddleboard fin is attached underneath the paddleboard. It is submerged in the water and is designed like the fin of a shark or a dolphin. This is not merely a coincidence – it is a design choice that helps improve its functionality.
A fin helps improve the performance of your paddleboard. Firstly, it cuts through the water and allows you to move with less resistance. Secondly, and more importantly, it allows you to track through water or move in a straight line with minimum effort.
Without a fin, on each stroke of your paddle, your paddleboard would turn drastically and it would be incredibly difficult to manoeuvre anywhere. A replacement paddleboard fin also helps with speed and control – but this depends on the design, and setup of your fins.
Important paddleboard fin terms
The paddleboard fin has a design much like a dolphin or shark fin. To understand how it works, there are some important terms that you should learn – most notably rake, height, area, and base.
The rake of a paddleboard fin is the angle (measured in degrees) at which the fin curves from the base. Rake directly impacts how the fin can cut through the water. Upright fins generally have more drag, whereas fins with a more pronounced rake will cut through the water easier.
Simply put, the height is measured from the base of the fin to its tip. This is an important factor to calculate the overall surface area of the fin, and its suitability for different purposes. Generally, a taller fin will have an increased drag, although this can be counteracted by a smaller base.
The area of the fin is its surface area. There is a commonly used formula to calculate this – base length x the fin height x the width.
The base is essentially the part of the fin that is attached to the paddleboard and the bottom section of the fin. As noted above, the width of the base affects the overall area of the fin. Also, the shape and design of the base can affect tracking and performance.
What are the common paddleboard fin setups?
When looking at buying a replacement paddleboard fin, you should also consider your setup. There are three main configurations that you can have for paddleboard fins – single fin, 2+1, and 4+1 – we have described each setup below.
Single Fin Setup
The simplest fin setup is the single fin. This is a single paddleboard fin attached in the centre of the board at the rear. A single-fin setup is considered the best option for flatwater paddleboarding.
As there is only one fin, however, it can reduce control and stability. A single fin setup is ideal for those with more skill and experience, and those who want to travel faster as it has a reduced drag.
2+1 Fin Setup
Next, we have the 2+1 fin setup. This is the most common paddleboard fin configuration. For this setup, there is a large central fin that has a smaller fin on each side. The advent of three fins underneath the paddleboard provides far greater stability and means you do not have to have expert balance.
Most beginners will benefit from a 2+1 setup. This is because it is the most stable configuration and means that the user can concentrate on their paddling skills and control, without the constant fear of falling off. However, the 2+1 setup also has more drag and thus reduces your overall potential speed.
4 Fin Setup
Lastly, we have the 4-fin setup. As you have guessed, this setup features four smaller fins – two on each side. This configuration offers great balance but also gives more control and allows for greater speeds.
The two smaller fins on each side provide stabilization. Also, because there is no large central fin, you still get a reduced drag and therefore more speed. This is generally another paddleboard fin configuration for more experienced paddleboarders.
How can the fin placement affect your paddleboarding experience?
Once you have chosen your paddleboard fin setup, the actual placement of the central fin (if you have one) is also important. The fin placement can affect the performance of your paddleboard in different water conditions.
On standard paddleboards, the US fin box (which is a standard fin slot design) has a fin slot that is larger than the base of the fin. This is so that you can place the fin in different positions to suit different conditions.
Placing the fin at the front of the slot, towards the nose is ideal for surfing and in slower, crowded waters. This positioning should increase manoeuvrability and give you greater control over your turning.
Alternatively, placing the fin at the rear of the slot, towards the tail of the paddleboard is ideal for long-distance journeys. This placement will improve the speed and tracking of your paddleboard which is greater for longer journeys, or where you are travelling predominantly in a straight line.
Lastly, for a balance between tracking and manoeuvrability, simply place the fin in the middle of the fin slot. This is a great place to start and is the ideal position for a beginner. This placement offers a mix of control and speed.
Why could you need a replacement fin?
So why is it important to have a replacement paddleboard fin handy? It is important because the fin is one of the most fragile parts of the paddleboard. It is also the part that is most susceptible to damage due to its positioning underneath the board.
Paddleboard fins can easily snap off or break if you accidentally paddle over a submerged rock, for example. Also, they can easily become damaged, bent, or broken if you do not take care when taking your paddleboard out of the water. People often make the mistake of dragging their paddleboard from the water – this is a huge no-no and can cause serious damage to the fin.
Also, over time due to constant use in the water, paddleboard fins can degrade in quality, wear down, and become misshapen.
If you try to use a broken or degraded fin, the performance of your paddleboard will be reduced. You may struggle to control the paddleboard properly, and it could also be potentially dangerous. This is why it is important to take care of your paddleboard, and always have a variety of replacement paddleboard fins available.
These are relatively inexpensive items and they do not take up much storage space. Therefore, save yourself hassle and stress, and carry a spare set with you when paddleboarding!
The Best Replacement Paddleboard Fin Products in 2021
Now that you have a clear understanding of why a replacement paddleboard fin is important, we have provided four high-quality products for your consideration. These four replacement fins are great spares to have ready if your current fin should deteriorate or get damaged.
1. Goosehill 9” SUP Fin
- Height: 9”
- Base: 7”
- Rake: 30-degrees
- Link: Here
The Goosehill 9” SUP Fin is a durable and robust paddleboard fin that should be compatible with most standard paddleboard designs. It has a simple slide-in mechanism and a quick-release function. This means you should be able to change it quickly with minimum fuss.
Also, you do not need any tools or screws to fix this fin in place which is highly convenient. The nylon construction of the fin makes it durable and stiff, while still giving it flexibility. The design should also give you maximum manoeuvrability and tracking.
2. OCEANBROAD 8” Surf SUP Fin
- Height: 8” / 9” / 10”
- Base: 7.1”
- Rake: N/A
- Link: Here
The OCEANBOARD 8” Surf SUP Fin offers a different fixing mechanism that utilizes a single screw. It is not as quick to install as the Goosehill Fin, but the single screw is designed in such a way that doesn’t require any tools. It is also still simple to fix – just make sure that you check the fin mount of your paddleboard and size beforehand.
The fin is made from durable fibreglass-reinforced nylon, and the connection is made from marine-grade stainless steel. You can also get this durable paddleboard fin in a 9” and 10” design too.
3. UPSURF 9” Longboard & SUP Single Fin
- Height: 9”
- Base: 7”
- Rake: N/A
- Link: Here
Next, we have the UPSURF 9” Longboard & SUP Single Fin. This fin is suitable for use on both surfboards and paddleboards. It is made from superior reinforced nylon that can withstand high water pressure and UV.
For fixing, it uses a similar single-screw mechanism as the OCEANBOARD fin. Simply attach the screw through the O-ring and plate, and screw it to the box on your paddleboard. We also like that the screw is designed in such a way that it doesn’t require any tools.
4. SBS 10” Surf & SUP Fin
- Height: 10”
- Base: 6.5”
- Rake: 28-degrees
- Link: Here
Our last pick is the SBS 10” Surf & SUP Fin. The larger design of this paddleboard fin should allow it to hold well on flat water and make easy turns. It is made from glass-filled nylon and should be compatible with any SUP paddleboard with a standard 8.5” or 10.5” fin box.
There are some known incompatibilities, however, and we advise checking with the manufacturer beforehand to be sure. Like other designs, this paddleboard fin has a simple one-screw no-tool mechanism that is easy to attach.
Don’t Underestimate the Importance of the Paddleboard Fin
We hope you have found this guide useful. Many people underestimate the role of a paddleboard fin. Please don’t! As you can see from the above, it is a highly important part of your paddleboard and can greatly affect your experience and enjoyment. Don’t forget to check out our other paddleboarding articles for more info, such as our Beginners Guide to Paddleboarding and the Best Places for Paddleboarding in the UK.