Choosing the Right Surfboard Fin [2021 Update] + Guide

Flo Farmer
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Surfboard Fin Types: Your Detailed Guide

In this post, we’re clearing up some of the ambiguity around surfboard fins.

First, let’s get something out on the table. Surfboard fins are not rocket science. Better fins don’t automatically guarantee better performance.

While that may seem obvious, you’d be surprised how many people interpret their poor performance in the water to a fin that’s too small, too big, too hard, to soft or simply to vertical.

The truth is that surfboard fins play a minimal role in your performance and all they do is provide tracking and stability. Think of them as the rudder of a boat. They keep your board going the direction you want it to go, and they keep you in the center of your board.

To help you better understand surfboard fins, we’ve collected all the available information as well as a range of fin charts to help you make the right decision.

What is the difference between a swappable (Removable) and a glassed-in fin?

Swappable or removable fins offer convenience and price advantage, but are known to be less efficient than glassed-in fins. Swappable fins can fall off or be damaged easier as well.

In the past, removable fins were a must-have unless you wanted to ride only in perfect conditions. If you did take your board out in the ocean, then at least one fin had to be attached.

These fins typically are made of fiberglass, making them heavier than comparable glassed-in fins.

They are also waterproof and need to be glued in with a special resin that is formulated for this purpose. The major drawback of temporary fins is that they can get damaged or fall off as rides are often bumpy.

Later, production fins made of foam and urethane started to be seen, which were more stylish than the fiberglass ones, but still in my opinion were much less efficient.

The fins are made of softer materials, which allows them to break and get damaged.

They are less efficient than glassed-in fins, however, they are lighter and if properly glued to the board, are more durable and reliable.

The major drawback of such fins is lack of deep channels, which allow for easy water flow over the fins surface. This prevents the fins from self-pumping as you ride.

What are the different box types or fin systems?

As mentioned above, in the old days fins swam behind the surfboard. Today, boards are made with a hard foam core and a tough plastic skin. With the development of the resin transfer molding process (RTM) fins can be placed below the surface of the board, leading to a port-style slot, which makes fins substantially more aggressive.

Which is better: FCS or Future fins?

If you are just learning to surf and you have a shortboard we would suggest using twin fin set-ups.

What is the essential measurement in choosing a surfboard fin?

The essential measurement in choosing a surfboard fin is the length in centimetres to match up with your height and weight.

Since it is very difficult to measure in feet, for your convenience, the most commonly used measurements will be in cm. Generally, most surfboards will be measured in centimetres instead of feet. So it is important that you know exactly how to convert cm to feet and vice versa.

Here are some conversion values:

One foot equals to 12 inches (1 foot = 12 cm) One inch equals to 2.54 centimetres (1 inch = 2.54 cm)

If you know your size perfectly in feet, you can easily convert to cm. For example, if you are 6 feet tall, you can directly write down (6 feet = 183 cm).

You can also use the chart below to easily convert cm to feet and vice versa.

Sweep (Rake)

The first step is to narrow down your choice by deciding which of the two main fin designs you like more. Each fin type has its own advantages and disadvantages. If in doubt, just check out as many fin reviews as possible and read the descriptions carefully. Those descriptions will often tell you everything you need to know. Some of the most popular fin designs are the Quad, Thruster and Firewire.

The quad (also sometimes known as Box fin) is the most common fin type, and has four sections. Its main advantage is that it performs well in a wide range of wave conditions. This fin design is also used on long boards, as well as fish and short boards. These types of boards don't necessarily need to be super fast, but instead need to be responsive and well balanced. On a longboard, you can do almost everything with a quad fin: Shred barrels in mushy waves, cruise with friends along rippable peaks, or do some light carving. However, if you decide to go for a quad fin then please keep in mind that some shallow waves require shortboard-like speeds. Good examples are small shore breaks and other spots where you need to blast trough the whitewash, or hit the lip with your board held at a high angle. But if you’re a wave-rider that likes to go fast on point, you’re better off with something else.

Toe (Splay)

You’ll want to look for fins that have a “toe (splay)” or also known as “paddle fins”. These fins flex and help the board track straighter with less effort. You will be able to paddle further and recover from poor wave entries more easily.

Flat or vee fins are best suited for a surfer who has a longboard and is looking for a faster board that needs less effort to paddle. It will vary board to board but to take a general look, if your board is 10 inches or longer you can likely run a flat to vee fin.

Base (Length)

When fitting a fin think about each of its individual dimensions; the length of the fin base should be the same as the length of your surfboard. Also, make sure that the depth of the fin base matches the starting point of the rocker of your surfboard. Next, match the volume of the fin with the volume of your board. But to measure volume you will need to find out the thickness of the surfboard, which is usually printed on the bottom of the board behind the center fin.

Ideal fin size is usually a function of experience and size of board. Bigger boards need bigger fins to generate the same amount of drive as a smaller board would. A smaller fin will still drive your board but its benefits (lift, maneuverability) will be significantly reduced.

Different technologies and fin combinations provide different benefits to your surfing, think of it as being a tool, the tool will only be able to help you if you know how to apply it correctly. There is not one fin for all, some will be suited for your style and riding conditions better than others.

Foil

The most basic part of a wing is its foil. Foil design is one of the most important design considerations in a wing kite.

Foil design is often a tradeoff between two different foil types, “conventional” and “vertical”.

Conventional fins are mounted at an angle to the wing chord, similar to the beavers tail on a surfboard. A conventional foil is less efficient than a vertical foil, but will usually perform better as a brake in lower wind speeds, or in the lull after a gust. Conventional foils are typically used in wings from 1.6m to 3m in span and are usually found in the nose.

Vertical foils are mounted perpendicular to the wing chord, similar to a surfboard fin or a fish tail. Vertical foils are more efficient than conventional foils, but they will perform poorly as a brake in low wind speeds, which makes them a poor choice for a kite in anything less than a light wind (<5 knots), or a kite that is very sensitive to brailing forces (light-wind freestyle). Vertical foils are usually best used in the tail of the kite.

When a vertical foil is located near the center of pressure, it becomes less efficient and may even perform worse than a conventional foil.

Flex

Flex fins are used mostly by surfers on long boards, but also in standups and body boards. They are made of a durable, flexible plastic. Flex fins are curved at the top. They form a concave surface and are long and thin. Flex fins range in sizes from 1.5 to two centimeters. They are available in different colors and styles.

The flex fin is very responsive and flexible. It has a large range of motion and is light in weight. Its unique ability to flex both in an upward and downward direction distinguishes it from the other types of fins. Flex fins can be fixed styles or split fins. Flex fins work best with short, wide boards as they help thicken the tail of the board in order to provide more support. In addition to providing stability to the board, flex fins also provide good speed, easily taking down larger waves. It is good for all-around surfing and for flat water.

Flex fins are great for beginning surfers to use in the body board. Surfers who like to try tricks can also experiment with flex fins. It also works for surfers who want to gradually move towards developing their sea skills instead of attempting higher waves.

Height (Depth)

If you want a light, responsive and more wave riding oriented surfboard, then a low profile fin (type in a fin that is 45 mm to 50 mm) is the most favorable. A low profile fin generates a better drag, so it is more sensitive to foot steering…that is, the fin respond to slight changes in foot movement, which will help you turn and move through the wave sequences quite effectively.

Higher fins (type in a fin that has a more than 60 mm height) give your surfboard stability, making them ideal for surfing on shorter days. Also, a higher fin provide more area for sitting, which is certainly important if you are 6’ plus and you want to keep your heels firmly on the board during the acceleration, as well as during the turns.

The good news is that today most surfboards, regardless of their shapes, come with both types of fin box (side or center). So the choice ultimately lies with you.

Cant

Ilevered vs. FCS (FCS 2 vs. FCS 3)

FCS2 (and 3) systems were designed and developed by FCS and made to work better with more FCS plugs.

It allows surfboard builders to have more options when making the board, as well as designers and shapers to spend less time in the shop.

FCS can take up any rank from 1-4 in their plugs, and their block location helps push the most out of your surfing experience.

They make the most surfboard fins and surfboard shapers use it.

Cantilevered or FCS…Let’s go back to the basics.

The holes itself will be the same so it’s a matter of preference.

What The Hell Is The Problem With FCS?

If you have surfed for a long time, you’ve probably known someone who has snapped their fins and blame it on FCS.

FCS fins are screwed on to the board and comes with a screw on each fin that screws into the rail of the board.

These screws are made of aluminum, but they have sharp edges.

They also do not allow you to change the location of the fins easily, so if the fins are in the wrong location, they are really hard to fix.

Frequently Asked Questions (FAQs):

Q: Does surfboard fin size matter?

A: Yes, it does. Although in recent years there's been a lot of buzz about the new directional, or 3D, fins, which offer more versatility in waves, the tried and true 4- or 5-fin setup still rules in the surf world.

Surfboard fin size is just as important as the rest of the board (and we'll touch on the rest of the board in the next question), if not more so. The fin interacts with the water, which is constantly changing temperature and velocity. When the fin, water, and wave come together as one, the results, as you know, are explosive, dynamic, and, at times, way too good to be true.

So, type of fin and fin size matter. As do other aspects like the board design, which helps you understand where the size is ideal on the board; whether it’s a thruster, quad, tri, etc. ” and also the size of your feet. If you have big feet, you’ll likely need a larger fin for your board to help cover the extra area on the bottom of the board.

Q: What is the difference between carbon-based and composite surfboard fins?