FCS vs Futures: which fins fit which surfboard
How to tell FCS, FCS II and Futures apart on a used board, which fins fit which box, what a new set costs, and what each fin setup needs.
· 7 minute read
The short answer
FCS and Futures do not fit each other, in either direction, and nothing joins them. FCS has two generations of its own. An FCS II plug takes FCS II fins, and it takes the older two-tab FCS fins once you add the silicone infill and grub screws from FCS's compatibility kit. An original FCS plug takes two-tab fins and nothing else. Glass-on fins are part of the board and never come out.
Telling them apart at a glance
FCS original: two round plugs, a screw in each
FCS II: one plug, and the fin clicks in
Futures: one long box, one screw at the front
Glass-on: the fin is part of the board
- FCS original
- Two small round plugs per fin, one behind the other, each with a grub screw you tighten with a fin key. The fins have two separate tabs. It came first, in 1995, and you still find it on plenty of older used boards.
- FCS II
- One plug per fin. Its own fins need no screw and no key: you press the fin in by hand until it clicks. FCS brought it out in 2013, and it is the one FCS plug that takes both generations of FCS fin.
- Futures
- One long narrow box per fin, with a single screw at the front end. The fin's base is one solid piece along the length of the box, where an FCS fin has two tabs.
- Glass-on
- The fins are laminated into the board and do not come out, so there is nothing to buy and nothing to lose. Common on longboards, single fins and older shortboards.
- Single fin box and 2+1
- A long centre track the fin slides along and is held in by a screw, usually on a longboard or a midlength. 2+1 is that centre box with a small side box near each rail.
FCS, FCS II and Futures side by side
| System | In the board | Held by | Takes |
|---|---|---|---|
| FCS original | Two round plugs per fin | A screw in each plug | Two-tab FCS fins only |
| FCS II | One plug per fin | Clicks in, no tool | FCS II fins, and two-tab FCS fins with the compatibility kit |
| Futures | One long box per fin | One screw at the front | Futures fins only |
FCS's own US store, read 2026-10-19: the FCS II Compatibility Kit (one centre and four side infills, ten grub screws, a key) for two-tab fins in FCS II plugs, and three two-tab sets still sold for original plugs. The years are from Wikipedia's article on FCS: the original system patented in 1995, FCS II introduced in 2013.
On the boards listed here, Futures comes up more than everything else together. Of 192 used boards on 19 October 2026, 75 named their fin system: 45 Futures, 26 FCS II, 3 FCS original and 1 single fin box. If you own fins already, boards with Futures boxes and boards with FCS II plugs are one filter away,.
Fin setups: what the boxes let you ride
The system is the shape of the box. The setup is how many boxes there are and where. A used board's setup is fixed when it is built, so it tells you which fins to buy as much as the system does.
| Setup | Boxes | Usually on |
|---|---|---|
| Single fin | One long centre box | Longboards, midlengths, eggs |
| 2+1 | A long centre box and a small box near each rail | Longboards and midlengths |
| Twin | Two, one near each rail | Fish and twin fins |
| Thruster | Three: two near the rails, one in the centre | Most shortboards, step-ups and grovelers |
| Quad | Four, two near each rail | Fish, grovelers and some shortboards |
| 5-fin | Thruster and quad boxes on one board | Shortboards and grovelers made to ride either way |
Five boxes is the useful one to find on a used board, because it rides as a thruster or as a quad and you pick on the day. Three boxes rides as a thruster, or as a twin with the centre fin out, which feels loose and slides more than a real twin does, because thruster side fins are smaller than the fins a twin is shaped around. If a twin is what you want, used twin fins are built for it.
Check the boxes before you pay
- Push each fin sideways and watch the box
- Push gently and look at the plug or box, not the fin. One that shifts in the board has broken loose from the foam around it, and water gets in there.
- Look at the resin around every box
- Hairline cracks in a ring around a plug, or a brown stain beside it, mean water has had a way into the foam.
- Try every screw
- A grub screw seized in an old FCS plug, or a screw stripped in a Futures box, means a fin that will not come out or will not stay in. Take a fin key and turn each one before you agree anything.
- See the fins that come with it
- Ask what is included, and look at it. A set with a chipped tab or a cracked base is a set you will be buying again.
A box that has come loose is a repair for a ding shop, and worth a lower price. The full inspection route covers the rest of the board, nose to tail.
If the board comes with no fins
| System | Sets | Cheapest | Most cost |
|---|---|---|---|
| FCS II | 59 | $40 | $134 to $155 |
| Futures | 100 | $42 | $125 to $160 |
surffcs.com and futuresfins.com, read 2026-10-19, every thruster set each store listed that day. "Most cost" is the middle half of them. Prices in Bali surf shops were not checked.
Take the price of a set off what you were going to pay, or ask the seller to put one in. The cheapest sets in both stores are the soft and moulded entry fins, 36 to 54 dollars. A fibreglass or carbon thruster set starts at 65 to 75, and most cost 125 to 160. For original FCS plugs, FCS still sells three two-tab sets, from 36 to 128 dollars. Plenty of sellers leaving Bali have a spare set in the bag and had not thought to mention it.
Common questions
- Do FCS fins fit FCS II boxes?
- Yes, with FCS's compatibility kit. The older two-tab fins go into an FCS II plug with a silicone infill that fills the gap at the front and grub screws that hold the fin. It does not work the other way round: an FCS II fin will not fit an original FCS plug.
- Can I put Futures fins in an FCS box?
- No. Futures and FCS are different shapes and neither fits the other, and no adapter joins them. Buy the board that matches the fins you own, or budget for a new set.
- How do I tell FCS II from Futures at a glance?
- Futures is one long narrow box per fin with a screw at its front end. FCS II is a rounded plug with no screw, and its fins click in by hand.
- What is the difference between FCS 1 and FCS 2?
- FCS original, from 1995, holds each fin by two tabs in two small round plugs, with a grub screw in each. FCS II, from 2013, uses one plug per fin, and the fin clicks in with no tool. FCS II plugs take the old fins with a kit; original plugs do not take FCS II fins.
- Can any fins go in any board?
- No. A fin fits the box it was made for: Futures fins in Futures boxes, FCS II fins in FCS II plugs, and two-tab FCS fins in original FCS plugs, or in FCS II plugs with the kit. A board with glass-on fins takes none at all. Look at the bottom of the board before you buy fins for it.
- Can I ride my thruster as a twin fin?
- Yes, by taking the centre fin out. It will feel looser and slide more than a board built as a twin, because thruster side fins are smaller than twin fins. A board with five boxes gives you a thruster and a quad, and is the more useful one to find used.
- Is FCS II or Futures better?
- For a used board, the better system is the one your fins already fit. Both makers sell sets from entry level to their top riders' models at similar prices: in their US stores in October 2026, most thruster sets cost 125 to 160 dollars on Futures and 134 to 155 on FCS II.
Filter by fin system
The fin system is a filter here, and it sits in the spec table on every board that has one.
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