The Feel Guide

How to choose a surfboard fin.

A fin doesn't just hold your board straight. It decides how the board feels: how loose or locked-in, how much drive off the bottom, how far you can push the rail. Different fins, different boards, basically.

The four levers

  • Base

    Drive — how far the fin pushes you forward.

    Longer base = more drive off the bottom. Shorter base = more pivot. The single biggest difference between fins.

  • Depth

    Hold — how much the fin grips the rail.

    Deeper fin holds more line through a turn. Shallower fin breaks free easier — looser, skatier feel.

  • Sweep / Rake

    Turn radius — how tight or wide the arc.

    More sweep = wider, drawn-out turns. Less sweep = tighter, snappier turns. Rake describes the fin's overall shape from base to tip.

  • Foil

    Release — how the fin lets go of water.

    Flat-side foil drives. 50/50 foil glides. Asymmetric foils mix the two for distinct heel/toe feel.

Setup types

  • Single

    Feels like: Trim, glide, pivot off the tail.

    Ride when: Logs and traditional mid-lengths.

  • Twin

    Feels like: Loose, drifty, fast.

    Ride when: Fish, mid-lengths, or a log if you're feeling weird.

  • Keel

    Feels like: Skatey hold — speed without spinout.

    Ride when: Twin-fin fish in clean point waves.

  • Thruster

    Feels like: Vertical, snappy, predictable.

    Ride when: Performance shortboards.

  • Quad

    Feels like: Fast and drivey, less drag than thrusters.

    Ride when: Bigger waves, faster lines.

Choose by feel

  • I want it stable

    Feels like: More hold, more confidence, less twitch.

    Ride when: Choose more depth or a larger single fin. Move it back in the box for extra hold.

  • I want it loose

    Feels like: Easier release, tighter turns, more slide.

    Ride when: Choose less area, less rake, or move a single fin forward in the box.

  • I want more drive

    Feels like: More push out of turns and more down-the-line speed.

    Ride when: Look for more base. Keels and fuller twins are the fun end of this.

  • I want it cruisy

    Feels like: Smooth trim, easy glide, fewer surprises.

    Ride when: Start with a balanced single fin and tune from the centre of the box.

  • I want it weird

    Feels like: Different lines, new timing, cheap board experiment.

    Ride when: Try a twin-style setup where your board allows it, or swap colour and template before buying another board.

Fin systems

Three boxes most boards use. Get the system right and the rest is feel.

  • US Box

    Single rectangular box, screw + plate.

    The original. On most logs and traditional single-fin boards. Fixed plate keeps the fin straight; screw fixes it forward or back to tune trim.

  • Futures-style

    Single screw, single box.

    Common on modern boards — fish, mid-lengths, shortboards. Quick to swap, no extra plate. Fits standard Futures-style single-tab boxes.

  • FCS I-style

    Two-tab plug.

    The pre-FCS-II dual-tab standard. Two grub screws per fin. Still on a huge number of boards. If your board has FCS II boxes, these are not tool-free FCS II fins; see the note below.

FCS II compatibility: Our FCS I-style fins are dual-tab fins, not tool-free FCS II fins. Some FCS II boxes can accept dual-tab fins with compatible infills and screws, but check your board and kit before ordering.

Longboard fin sizing

A quick starting point for US Box single fins. Go smaller for a looser board, larger for more hold.

Board / surfer Feel Starting size
Mid-lengths or smaller logs Loose, easy to turn 7–8"
Most everyday longboards Balanced trim and turning 8.5–9.5"
Bigger logs or heavier surfers Extra hold and confidence 9.5–10.5"
Noseriding focus More hold while walking forward 10–11"
Not sure Start in the middle, then tune in the box 9"

Three setups worth trying

The questions everyone asks

  • Will a different fin make my board feel different?

    Yes — more than most surfers expect. Swapping fins is the single cheapest way to change how a board surfs.

  • Can I twin-fin a longboard?

    Absolutely. We have a story page on it: Twin fin a log.

  • Do you ship internationally?

    Yes — every coast. 7–14 days for in-stock and made-on-demand orders.