There are five major fin systems for surfboards:
So how are you supposed to determine which fin system your surfboard currently uses? It's pretty easy. Check it out:
The best place to begin is to determine whether you have an FCS fin box or a Futures fin box, as these are the two most common and widely used fin configurations found on nearly all modern surfboards.
Flip your board around and start by looking at the fin boxes.
An FCS fin is shaped with two small boxes on the base of the fin. These two boxes are placed into two separate tabs within an individual fin box. So, If there are two separate tabs/holes within each of your fin boxes, it's FCS.
If each fin box looks like one single slit/opening, as in there are no separate tabs within each box, and the box appears like one individual long slot, then it's a Futures set up. A Futures fin box will also have a fin screw placed at the top of the fin box.
The entire base of a Futures fin is placed into this single groove, versus inserting the two separate tabs of an FCS.
When you hear the term "FCS fin system," this refers to a fin system meant explicitly for surfboard fins created by one of the most popular and well-liked fin companies to exist- you guessed it, "FCS"- standing for fin control system.
However, FCS fin systems now come in two versions- the FCS Originals and the FCS II's. So what's the difference, and which one do I have?
Zoom in a bit closer after ensuring that you have an FCS fin box and not a Futures fin box to answer your question.
We'll start with FCS II, which is the newer of the two versions because it's easier to tell that you don't have an FCS II fin box (and therefore, you have an FCS Original) than it is the other way around.
FCS II fins are a removable fin system that requires absolutely no screws. Yup, they simply pop right in and out of the fin box with little effort! It's quick, easy, and far less hassle than unscrewing FCS Originals to make a quick fin change.
To determine if you have an FCS II fin box, take a look at the two separate holes in each individual box. If the front hole is larger than the back, it's an FCS II. Also, look for a small orange piece protruding from within the front hole of each fin box, as this is indicative of FCS II.
On the other hand, if the holes of each tab are the same size, and if there is no orange piece within the box, then you have FCS Originals. Lucky enough, an FCS Original fin can be inserted into a newer FCS II fin box with the available attachment piece.
However, this cannot be done the other way around, and an FCS II fin will not work in an FCS Original fin box.
Both of these surfboard fin companies are popular for a reason, and that is because they shape incredible, high-performance fins utilizing innovation and technology. So really, determining which one is better is best approached through experience and creating a personal opinion through trial and error. With this, there are a few common points that surfers tend to argue over each, including:
Chances are, your surfboard probably isn't a glassed-in fin system. A glassed-in fin refers to a fin that has been permanently shaped into the surfboard and is therefore not removable. Glassed-in fins are usually found on retro-surfboards, as this was the first style of the fin to exist and are usually only reserved for custom surfboards or special replications of old-school shapes.
You'll know if your surfboard's fin(s) is glassed in by looking at it. See it laminated to the surfboard with a layer of epoxy? No way to remove it? It's glassed-in, so there is no need to worry. That's your fin for life. And with this, you do receive the benefit of a smooth, sturdy fin with unique flex abilities.
With the fin glassed onto the base, it's extremely sturdy with no flex close to the surfboard deck but super flexible at the tip, offering a surprisingly high level of performance. You've just got to learn the specific fin and how it responds to various turns and conditions to bring out the best in it.
Next, let's dig into single fins, as single fins are a broad term. Tons of companies make them (not just FCS and Futures), and they are meant for a wide range of surfboard styles- longboards, fun shapes, retro single-fins.
The easiest way to determine if your fin is a standard single fin configuration is to again look at it. Is the box located in the center of the surfboard tail? Is the fin box longer than six inches? Is there a groove halfway between the top and bottom of the fin box? Then it's a single fin.
To attach a single fin/longboard fin, first place the small square plate into the bottom of the fin box so that the tip of the fin 'points' towards the tail. Use your screwdriver to carefully adjust the plate's placement.
Next, Insert the small metal rod attached to your fin into the groove, as this allows you to slide the fin to your desired placement.
Line up the screw-hole to meet the square plate, insert your screw, and tighten it firmly without overdoing it. You're good to go!