Surfboard Fins Guide: FCS II vs Futures, Fin Setups, Sizes and How to Match Fins to Your Board
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By Chris O'Shea and Anna Nikstad, Welcome Board Store, Mornington Peninsula
Fins are the cheapest way to change how your surfboard rides. We've had boards we didn't love turn into favourites with nothing more than a different set of fins, so before you write a board off, it's worth understanding what's going on under the tail.
This guide covers the two big fin systems (FCS II and Futures), fin setups from thruster to quad, twin and single, fin size by rider weight, template, foil and flex, materials, and how we match fins to boards, including the Channel Islands boards and Christenson fins we stock.
Quick answer: First check your fin box. FCS II and Futures fins are not interchangeable. Then pick your size by body weight (most adult surfers land in a medium or large), and choose a template: neutral if you're not sure, rake for more hold and drive in bigger, open waves, pivot for tighter turns in quick beach breaks. If you only buy one set, a medium flex all rounder like the Futures F6 Legacy or FCS II Performer PC is a safe place to start.
FCS II vs Futures: which fin system do you have?
Almost every modern surfboard comes with one of two removable fin systems, and the fins only fit their own system. You can't put Futures fins in FCS II plugs or FCS II fins in a Futures box.
| FCS II | Futures | |
|---|---|---|
| What's in the board | Two small plugs per fin | One long, single box per fin |
| How the fin locks in | Tool free: the fin clicks in and out | One grub screw tightened with a fin key |
| How to spot it | Two short slots per fin | One long slot per fin |
| Feel | Easy, fast fin changes | A solid base that sits deep in the board for a connected feel |
In our Futures fins video, Chris explains why some surfers love Futures: the long, solid base sits inside the board and gives a more connected feel, a bit like a glassed on fin. FCS II's big win is convenience. You can swap fins at the beach in seconds with no key.
Honestly, both systems are excellent. Choose fins for the system your board already has, and if you're ordering a new board, pick the system you already own fins for.
Old FCS plugs: if your board has the older two tab FCS plugs (with small grub screws), FCS II fins won't fit them. Original FCS fins will. If you're unsure what you've got, bring the board in or send us a photo.
Shop FCS fins, Futures fins or all surfboard fins.
Fin setups: thruster vs quad vs twin vs single
Thruster (three fins)
The thruster is the standard for shortboards because it does everything well: drive off the bottom, control at speed and a pivot point to turn from. The centre fin adds hold and predictability. If your board has three fin boxes, start here.
Good sets: Futures F6 Legacy (neutral, medium), Futures R6 Legacy (rake, medium), FCS II Performer PC, FCS II Mick Fanning PC (medium).
Quad (four fins)
A quad drops the centre fin and puts two smaller fins at the rail. With no fin in the middle, water flows straight out the tail, so quads feel fast down the line, loose in small surf and hold well on the rail in hollow waves. They can feel less pivoty than a thruster in the pocket.
Good sets: Futures F6 Legacy Quad, FCS II Harley Quad (designed for performance longboards). Shop all quad fins.
Five fin boards: many boards, like the Channel Islands Solution, have five boxes so you can ride them as a thruster or a quad, and the Solution can also go 2+1. If your board has five boxes, keep your thruster set and add a pair of quad rears, like the Futures Neutral Quad Rears (M) or the FCS II Mayhem Driver PC Carbon Quad Rears. It's like getting two boards in one.
Twin and twin + 1
Twin fins are fast, skatey and loose, and they love small, soft waves on fishes and twin specific boards. Big keel style twins suit traditional fish, while modern upright twins suit performance twins. A twin + 1 (also called 2+1) adds a small centre trailer for extra control without losing the twin feel.
Good sets: Futures Christenson Fibreglass Twin, FCS II Modern Keel PG, FCS II Mark Richards Twin + 1, Futures Mark Richards Fiberglass Twin + 1. Shop all twin fins.
Single fin and 2+1 (longboards and mid lengths)
Longboards and logs usually run a single fin in a long centre box, sometimes with two small side bites (2+1). A bigger, raked single gives a smooth, stable trim line for noseriding; a smaller, more upright single turns more easily. Most logs run something around 9" to 10".
Good options: FCS II Christenson PG Longboard Fin (9"), FCS II Connect 9 GF, and for mid lengths the FCS II Mid Carver 2+1 PG. Shop single fins.
Fin size by rider weight
Fin size is mostly about how much you weigh. Bigger fins give more hold and drive; smaller fins feel looser. Here are the brands' own size guides.
| Size | FCS rider weight | Futures rider weight |
|---|---|---|
| Extra small | Under 55 kg | About 34 to 52 kg (grom) |
| Small | 55 to 70 kg | About 48 to 70 kg |
| Medium | 65 to 80 kg | About 55 to 80 kg (Legacy series) |
| Large | 75 to 90 kg | 75 kg and up |
| Extra large | Over 85 kg | n/a |
Sizes overlap on purpose. If you sit between two sizes:
- Size down for a looser, skatier feel in small waves, or if you ride a narrow, low volume board.
- Size up for more hold and drive in bigger, more powerful waves, or if you ride a wider tail.
Specialty sets (twins, quads and longboard fins) often use combined sizes like M to L. Always check the weight range on the product page. For groms, the Futures Jack Robinson Grom HC (XS) suits lighter kids on boards like the CI 2.Pro Grom.
Template: rake vs neutral vs pivot
Template is the outline shape of the fin, and it's the biggest factor in how a fin feels in a turn. Futures labels its templates clearly on the packaging and FCS describes them on each fin.
- Rake (swept back): more hold and more drive, and it draws your turns out. Chris finds raked fins suit bigger waves where you've got time off the bottom, and high performance boards with lots of tail rocker. Example: Futures R8 Legacy (L), FCS II Mick Fanning PC (L).
- Pivot (upright): tighter turns and a quicker trip to the lip. These are great in quick, punchy beach breaks, which is most of what we surf on the Mornington Peninsula. Example: Futures P6 Legacy (M).
- Neutral (in between): the board rides close to how the shaper intended. Example: Futures F6 Legacy (M), Futures F8 Legacy (L).
Our advice for a new board and one set of fins: start neutral. If the board feels loose and you want more hold, try a rake. If a wide board is drawing its turns out too far, try a pivot to tighten it up in the pocket.
Foil, flex and materials
Foil
Foil is the fin's cross section. Side fins are usually flat on the inside and curved on the outside so water creates lift and drive. Some speed oriented fins use a more cupped inside foil to squeeze water off the fin; Futures' Blackstix fins use what Futures calls a V2 inside foil. Centre fins are usually symmetrical (50/50). Flatter foils feel more controlled, more curved foils feel livelier.
Flex
Flex is how much the fin bends and springs back.
- More flex: a springy, lively feel that helps generate speed in small, weak waves. Light surfers can push soft fins in bigger waves, but heavier or stronger surfers can overpower them, so they stop giving feedback.
- Medium flex: the most versatile choice for everyday surf.
- Stiff: solid, predictable and controlled when the waves are good and you're going fast.
Materials and constructions
Futures labels each construction:
| Construction | Feel | When we'd use it | Example |
|---|---|---|---|
| Blackstix | Speed generating | Small waves when you need speed | Futures F6 Blackstix, R6 Blackstix |
| Honeycomb | Balanced, medium flex | One set for everything | Futures AM1 Honeycomb and the Legacy series |
| Techflex | Speed control, stiffer | Bigger, better waves | John John Florence Techflex (M), John John Techflex (L) |
| Fibreglass | Stiffest | Good waves and strong surfers | Futures Coffin Bros (M) |
As Chris says in the video, the stiffest he personally goes is Techflex, because he doesn't need a fin as stiff as fibreglass for most of the waves he rides. If you want really stiff fins, go fibreglass.
FCS uses different material names. Performance Core (PC) aims for a fibreglass feel at a lighter weight, Performance Core Carbon (PCC) adds carbon for a stiffer base, Performance Glass (PG) is stiff with a traditional fibreglass feel, and Glass Flex (GF) is moulded to mimic fibreglass flex. Examples: FCS II Performer PC, FCS II Mayhem Driver PC Carbon, FCS II H4, which FCS says is engineered for control and predictability at high speeds.
How to match fins to your board
- Check the fin system and number of boxes. FCS II or Futures, three boxes or five.
- Pick your size by weight, then adjust for the board. Wider tails and step downs can handle more fin; narrow, rockered boards often like slightly smaller or more upright fins.
- Choose the template for your waves. Pivot for quick beachies, rake for open faces and points, neutral if you're not sure.
- Choose the flex for the conditions. Softer for small days, stiffer for good waves.
- Experiment. A second set of fins is a lot cheaper than a second board.
Matching fins to Channel Islands boards
We stock a big range of Channel Islands boards, and the ones currently listed online come with Futures boxes (it's in the size option on each product). A few of our go to pairings:
- CI Better Everyday: a wide step down shortboard. Chris likes a pivot fin in this style of board (he rode a pivot in the original Happy Everyday) to tighten up turns in the pocket. Try the Futures P6 Legacy or the CI Upright 5 Fin Set, which was designed in collaboration with the Better Everyday program.
- CI Solution: a five fin small wave board. Run it as a thruster for up and down surfing, a quad for top end speed, or a 2+1. The CI Upright 5 Fin Set gives you thruster and quad options in one box.
- CI 2.Pro and Feb Shorty: high performance shortboards. These are where a raked or neutral fin in a medium or stiff flex comes into its own, like the Futures AM1 Honeycomb (an Al Merrick template) or the John John Florence Techflex (M).
- CI Happy Traveler and Goldie: step ups for good, powerful waves. Go rake and stiffer, like the Futures R8 Legacy (L) or Coffin Bros.
- CI G-Skate: CI designed it around a 2+1 (twin plus trailer), and says it also works with your favourite thruster set.
- CI Big Happy: made for bigger or older surfers wanting paddle power. Size your fins to your weight, often a large.
If you ride FCS II and want a CI template, the FCS II CI PC Reactor is a collaboration between FCS and Channel Islands designed for speed and tight turns in punchy, hollow waves. Shop all Channel Islands boards.
Christenson fins and custom boards
Chris Christenson's templates are a favourite for twins and logs. We stock the Futures Christenson Fibreglass Twin, a pivot style template with an oversized base for drive down the line and release off the top, and the FCS II Christenson PG Longboard Fin (9"), a classic log trim fin in solid Performance Glass.
We also take custom orders for Channel Islands and Christenson boards. Custom boards take time to build, so if you want one for summer or Christmas, ask us early about current lead times and we'll help you choose the model, dimensions, tail and fin setup. If you're still working out board size, start with our surfboard volume guide.
Fin accessories worth having
Keep a Futures Fin Key in your car if you ride Futures; a lost key ends a session. An FCS Go Light Fin Case keeps your sets organised and protected in the boot. Browse more in surf accessories.
Surfboard fins FAQ
Are FCS and Futures fins interchangeable?
No. FCS II fins fit FCS II plugs, and Futures fins fit Futures boxes. Older FCS plugs take original FCS fins. Check your board before you buy.
What size fins do I need?
Go by your body weight. In both brands, medium covers roughly 65 to 80 kg and large roughly 75 kg and up, with small and extra small for lighter surfers. If you're between sizes, size down for a looser feel or up for more hold.
Is a thruster or quad better?
Neither is better overall. A thruster is the most versatile and the best place to start. A quad is faster down the line and loose in small surf, and holds well in hollow waves. A five fin board lets you try both.
What's the difference between rake and pivot fins?
Rake fins sweep back and give more hold and drive with longer, drawn out turns. Pivot fins are more upright for tighter turns in the pocket. Neutral fins sit in between.
Do fins really make a difference?
Yes. In Chris's words from our fins video, "fins do make a difference with a board." Changing template, size or flex can change how loose or held a board feels.
What fins should a beginner use?
A medium flex, neutral thruster set sized to your weight, like the Futures F6 or F8 Legacy or the FCS II Performer PC.
What are the best fins for small waves?
Softer, speed generating fins (like Futures Blackstix), slightly upright templates, or a quad or twin setup if your board allows it.
Can I put quad fins in a thruster?
Only if the board has five boxes (or a quad setup). A three box thruster has no rear rail boxes for quad fins.
Ask us
Not sure which fins suit your board? Ask us. Bring your board into the shop on the Mornington Peninsula, hit us up on our socials, or email support@welcomeboardstore.com.au with your board model, your weight and where you surf, and we'll match you to the right set.
