Probably the most underrated element of a surfboard is the fin. It is essential that you choose the right fins for your style of surfing and your board in order to get the best level of performance from your surfing. There are three main aspects to the surfboard fin. First of all, the fins have to be attached or integrated, and that's pretty straightforward. Modern surfboards come with fin boxes, which make it possible to clip the fins in.
This means you can customise your surfboard based on the conditions. It also makes transporting your surfboard much easier, since without the fins, it can easily be stored in a surfboard travel bag. Retro boards, like Malibu's from the 60s and 70s, and two-fin fish boards have integrated fins.
Because clip-in fins weren't available when these boards were being made in the past. On a modern surfboard, fin setup and fin size and shape are the two most important factors. As you'll see below, there are a number of other variables to consider when choosing surfboard fins.
A surfboard's performance will be determined by the fin size. A larger fin will provide you with more hold and control in bigger waves. Smaller fins will be more forgiving, but you will lose a lot of control and drive in larger swells.
Fins are attached to boards by this part. You will be able to drive further down the line with a longer fin base. As a result, turns become longer. On the other hand, a short fin base will let you turn the board on a dime, but you'll get less drive from a wide, arcing turn.
Looking down the line of the fin, the fin foil has an aerodynamic shape. Under the board, this foil generates lift similar to the wings of a plane. Different foil shapes result in different levels of performance when surfing.
Fin foils come in a variety of types, each with its own characteristics. The side fins (on twins, thrusters and quads) are generally flat on the inside or sometimes curved inward, and convex on the outside.
Typically, the center fins are symmetrical in shape or have an equal foil on both sides. Usually, the center fins are on the back of thrusters (tri fin boards), single fins, or the rear fins of quads.
A fin's rake/sweep refers to how far back the fin tilts on its arc. The greater the sweep, the more time it takes for your turn to complete. This is perfect for bigger days with a long wall to carve on. Fin rake is less important in smaller, mushier waves, when you need as much pivot as possible from the fin.
The fin height is basically how far the fin extends away for the bottom of the board. A deeper fin is going to have more hold and stability than a shallow fin. A shallower fin will give you less hold, but once again turning easier, and allow you to cut back the tail of the board more aggressively.
A fin's cant is how much of an outside angle it has in relation to the bottom of the board. A fin with zero cant is positioned at 90 degrees to the base of your board. When the cant of your fin is greater than 90 degrees, your board will be more responsive through turns. In other words, you can get more drive through turns.
The term "fin toe" is a bit misleading. As a result, it reflects the angle at which your fins are pointing at your stringer. It only applies to the side fins on a board since the middle fin will always run down the stringer. Different fin toes influence your surfing performance just like cant. Your turns will be more responsive if you have a greater angle against the stringer.
As you now know more about all the more subtle variables that make up a surfboard fin, let's turn our focus to one of the most important features of the fin - its shape. Your surfboard's performance is directly related to the shape of your fin. A wide range of fin shapes will affect your surfing performance, from a single large fin to a quad setup with two larger and two smaller fins.
A fin's flex also has a direct impact on performance. In turn, it contributes to your ability to project turns, thereby affecting your speeds and influencing your control. Generally, a stiffer fin reaches its maximum flex during a turn and releases faster, allowing for faster turns. The drive is also generally lower.
Now that you have a basic understanding of the shape and size of surfboard fins, let's discuss the different fin configurations. Depending on how many fin boxes are on your board, you have a variety of options. Fin boxes usually range from one to five.
Longboards and longer shortboards typically have a single fin setup. It is the most traditional fin configuration for surfboards. A single fin setup tends to result in faster, more direct down the line surfing. Changing the position of the in will change the way you ride. A looser feel will be achieved by putting your fins forward. You will have more control if you move it further back.
Surfing with twin fins or dual fins will make you more playful, fun, and maneuverable. When surfing smaller waves, a twin fin setup will give you more speed. Twin fins allow for longer, more gradual turns.
A thruster is the most common configuration today and can be found on a variety of surfboards. Two of the outer fins are toed in toward the center of the board. Despite being flat on the inside, the outer fins will effectively track the water and increase speed.
The center fin is set back and close to the tail. The fin foil is symmetrical. Thruster setups are effective because they combine stability, control, and manoeuvrability. With a thruster fin box, you can also choose between twin fin or single fin configurations.
In a quad fin setup, the water is channeled to the end of the surfboard and out the tail for acceleration. The placement of two fins near the rails of your surfboard will also add stability and hold in big-wave surfing where maintaining a high line is imperative. Finally, quad fins are great for generating drive through turns.
In the world of surfboard fins, there is a duopoly at work. FCS and Futures fins are available. Both of these companies have their own unique system. FCS fins have a patented two tab system. In the past, these two tabs were secured into the fin box with screws on either side of the fin.
FCS recently introduced the FCS 2 system, which eliminates the need for screws. You can now install and remove your fins in seconds without any screws or tools, so you'll be in the water faster. Futures fins make use of a single continuous rail system on their fins. It is perforated to keep the fins as light as possible and drive the highest levels of performance. Future fins are also secured in place with two screws.
The main difference is that they are secured at either end of the fin, rather than on either side of the fin. It is important to note that the FCS and Futures fin systems are incompatible. If you're buying a board, or getting one shaped, it's important to know upfront which fin system you're looking for.