Area - The area of the fin is, broadly speaking, how big the fin is. Bigger fins will have more hold, which means more control, especially in bigger surf. Smaller fins will have less hold, meaning it will be looser and there will be a higher likelihood that you will slide out if you push it too hard. This doesn't necessarily mean you should go for bigger fins all the time, as these are slower, as there is more fin in the water and therefore more friction. Both FCS and Futures fins are categorised as small, medium and large (futures also have extra small) and the size you choose depends on your weight, with heavier surfers choosing larger fins. Conversely, if you are a powerful surfer and push hard through your turns, it is probably worth you getting fins that are slightly larger, as these are less likely to slide when you go full blown Mikey Wright on the shoulder (of course, to do a proper Mikey man-hack you do need a mullet) .
Depth - This refers to how far the fin extends away from the board. Similar to area, a fin that extends deeper into the water is going to have more hold, whereas a shallow fin will be looser and so you will get more release through turns, meaning the board is more likely to slide.
Base - This refers to the length of the fin at the position closest to the board. The larger the base of the fin, the more drive it will have. Fins with a lot of drive will result in longer and more drawn out turns, however they will also make it slightly easier to generate speed through these turns. Fins with a smaller base will turn sharper and more easily.
Rake/Sweep - The rake, or sweep, of a fin refers to how much the tip of the fin arches back. the more sweep/rake a fin has, the more drawn out your turns will become and the less pivot it will have. The more upright the fin, i.e., the less sweep/rake it has, the more pivot the fin will have and the less drawn out your turns will be. This is better for snappy turns, where you need to change direction quickly, for example in punchy, quick beachbreak conditions. A fin with more rake/sweep is better for longer cutbacks, which will be more suited to open faced powerful waves.
Foil - The foil is the shape of the fin from front to the back. In terms of hydrodynamics, this is the most important aspect. Centre fins tend to have a 50/50 foil which means they are symmetrical. This creates an even water flow and increases stability. Flat foil fins are rounded on the outside edge (like a normal 50/50 foil fin), however they are flat on the inside edge. This foil type allows for quick directional changes. Inside foil fins are rounded on the outside edge and concave on the inside. This helps water flow smoothly and thus allow you to maintain more speed through turns, whilst also being somewhat responsive like flat foil fins. Finally quad rear fins tend to use 70/30 or 80/20 fins which have a greater curve on one side then the other. These provide a mix of stability and turning sensitivity. Futures fins also have 'V2 foils' which incorporates an inside foil toward the base of the fin and a flat foil toward the tip of the fin.
The materials with which your fins are constructed from can make just as much difference as the shape of the fin. This manifests itself through the flex properties of the fin. Both futures and FCS have a range of fins that are constructed from different materials. Flexible fins will offer projection out of turns, which means speed, as during the turn the increased pressure against the fin causes it to bend and flex. As you begin to straighten out your turn, the pressure against the fin decreases and thus it can snap back to its original position, pushing the water giving you speed in the process. However if your fin is too flexible ,it can be wobbly and unpredictable in big surf. Therefore, finding a balance between flexibility and stiffness is crucial. Those of us who are lucky enough to surf bigger waves and don't need to create speed can use stiffer fins as these offer slightly more control, however if you are surfing smaller waves that require you to pump to create speed, flexible fins can offer a great relief.
Below we will outline all the different constructions that both FCS and Futures offer.
Soft Flex - Precision moulded using flexible urethane. This is beginner friendly fins with the maximum amount of flex offered in any FCS fins.
FCS II Performer Soft Flex. Ideal for foam boards or crowded beaches.
Glass Flex (GF) - Precision moulded from engineering grade polymer. These fins are also good for beginners as they offer good flex, allowing you to maintain speed through turns.
FCS II Performer Glass Flex. A balanced template with neutral rake, good for all waves.
Neo Glass (NF) - This is a lightweight, moulded construction using a high fibreglass content (50%) and marine grade polymer. These fins offer less flex than Soft Flex and Glass Flex fins, and so will create a more immediate response through turns.
FCS II Reactor NG. A relatively small amount of sweep and an upright template means these fins goes well in short, punchy beachbreaks.
Performance Core (PC) - These have a slightly higher fibreglass content (55%) compared to Neo Glass fins. They use fibreglass resin, and a hex core, to achieve a lightweight fin, with good flex and an immediate response through turns.
FCS II Performer PC. Solid all around fins.
Performance Core Carbon (PCC) - These are similar to PC fins, however again have a slightly higher fibreglass content (60%) but also make use of carbon strips in certain parts of the fin, to create specific flex patterns. These are favoured by powerful surfers.
FCS II Accelerator PCC. A larger sweep and more elongated template lends these fins to longer running waves.
Performance Glass (PG) - These are machine cut from solid fibreglass and are often used by pro surfers as they offer stiff flex pattern with immediate response through turns.
FCS II Power Twin PG. A twin fin with big area, full tips, a moderate rake, but not too much depth, creating drive and release off the top.
Control - Futures Control series is made from fibreglass with some carbon fibre. The Carbon fibre adds strength, reduces weight, and increases responsiveness. These are the stiffest fins in the Futures line up.
Futures Pyzel Control. A wide base gives this fin plenty of drive. Perfect for the powerful waves of Hawaii.
Techflex - These are fins for those who surf in big powerful waves. They use a honeycomb core (similar to the Hex Core fins from FCS) which reduce the overall weight of the fin dramatically. The carbon in the base and the tip keep the fin stiff and therefore increase control in big surf. They are slightly more flexible than the Control series.
Futures AM2 Techflex. A flat foiled fin with Techflex construction ensures stability and control.
Honeycomb - These fins sit in the middle of Futures range in terms of flex vs control. These are made using a lightweight hexagonal core which reduces weight and maintains some flex. They are more flexible than the Techflex and Control series. Honeycomb fins are a good all around fin, and so if you surf in small mushy waves, as well as big powerful ones, this is a good option for you.
Futures Jordy. A wide base and lots of rake will provide plenty of drive and control through big sweeping turns.
Alpha - Alpha fins sit in the same flex range as the Honeycomb series. They are made using a new carbon fibre infused material that is lighter than honeycomb but just as strong. Alpha fins have added thickness at the base of the fin and reduced thickness at the tip, giving this fin extra drive.
Futures F6 Alpha. A balanced fin, good for all conditions.
Generation - Generation fins are made using honeycomb, uni-directional, and bi-directional fibre glass and make use of V2 foil, which is meant for speed and drive. The fins feature bi-directional (the fancy term for 'normal looking') carbon fibre at the base which creates stiffness and rigidity. There are strips (uni-directional) of carbon fibre then running from the front half of the base vertically up the fin. This secures the leading edge of the fin, concentrating flex to the tip, which is not reinforced with any carbon fibre and so maintains the natural flexibility of the material. Finally, Generation fins use epoxy resin as it is lighter and stronger than polyester resin.
Futures HS3 Generation. A stiff based fin that flexes at the tip. Good for generating speed.
Blackstix - Blackstix fins are designed for generating speed. They use strips of carbon fibre running from the base through to the tip of the fin that controls the way the fin flexes. There is also bi-directional carbon fibre running in an arc from the base of the fin toward the leading edge, which stiffens the base, adding drive, but leaves the tip free to flex. Finally, they are constructed with epoxy resin, for its reduced weight and resilience. The result is a fin that has plenty of drive and that becomes progressively more flexible the further toward the tip.
Futures AM1 Blackstix. The V2 foil and blackstix construction ensure a lively tip and an even easier ability to generate speed.