FCS II Modern Keel Review

9.2/ 10 Estimated score

9.2

Estimated from 2 independent sources (no numeric scores published)

Average price$134Range $134–$134 across 1 retailersSee sources

FCS's modern take on the classic fish keel — long base for speed and glide, straighter trailing edge for release, tuned for modern twin fins rather than 1970s fish shapes. The default upgrade for anyone running a twin-fin groveler in FCS II boxes.

View on FCS

Quick specs

System: FCS II
Type: Twin keel (2-fin)
Template: Modern keel — long base, moderate depth
Construction: Performance Glass
Rider size: 60–95 kg
Best for: Modern twin grovelers — Seaside, Mashup, Twinsman

The Modern Keel is FCS's answer to the classic fish keel updated for the modern twin-fin boom. Long base for speed, upright trailing edge for release — a middle ground between a 1970s Bing/Lis-style keel and the more upright MR TFX template.

Best matched with modern twins designed for looser small-wave feel: Firewire Seaside, Firewire Mashup, Album Twinsman (twin-only setup). If your board came with keel-shaped fins from the factory, this is the direct upgrade path.

Pros & cons

Faster and looser than an MR-style upright twin
Straight trailing edge releases the tail cleanly out of turns
Long base for straight-line speed and glide
Fits any FCS II board — vast majority of modern twins post-2016

Slidey feel on steep waves — not the fin for reef or hollow surf
Won't hold a hard rail as long as a MR TFX template
Twin only — no trailer included

How it surfs

Reviewers consistently pair the Modern Keel with the Seaside for the most popular groveler / small-wave twin-fin combination sold in FCS II boxes.

Note: this is a twin only — no trailer. To run twin+1, the FCS Original MR TFX (Dual Tab) is the reference set, but requires a different plug system.

Volume & sizing chart

Use the chart below as a starting point. Add half a litre if you are less experienced, subtract half a litre for a looser feel.

Size	Volume	Rider weight	Best for
One size	Base 5.06" / Depth 4.79"	60–95 kg	All

How it compares

Board	Best at	Wave range	Aggregate score
FCS II Modern Keel	Loose modern keel	Ankle to shoulder	9.2
FCS MR TFX Twin+1	Upright twin with drive	Waist to overhead	9.4
Futures Rasta Keel	Classic keel twin	Ankle to shoulder	9.0

Verdict

The default FCS II twin for modern grovelers. Loose, fast and clean off the top — the small-wave twin-fin benchmark.

Estimated score: 9.2 / 10

Estimated from 2 independent sources — none publish numeric scores. See sources below.

What reviewers around the web are saying

Surfex does not test gear directly. Below are independent retailer and editorial sources. When a source publishes a numeric score, it is normalized to a five-point scale; otherwise the source is listed without a score.

Estimated score

9.2/ 10

9.2

2 sources, none scored

Source	Score	Summary
Blink Surf — Modern Keel Twin Fin Set Review	No numeric score	"Upright keel template designed for traditional fish shapes. Lower sweep than most conventional keels, allowing tight-radius pivoting."
Hydro Surf Shop — FCS II Twin and Keel Range	No numeric score	"The fast, loose feel of a twinnie will put a grin on your face as you glide and slash your way through that 2ft summer slop."

Where to buy & average price

Listed prices come from verified retailer pages. The average price below is an unweighted mean of verified retailer prices — converted to USD (≈) when retailers list in different currencies. Click any retailer to verify the native-currency price.

Average price

$134

$134–$134 · 1 retailers

Retailer	Price	vs. average
FCS	$134	—	Visit

Frequently asked questions

Modern Keel vs classic keel — what changed?+

Straighter trailing edge and slightly shorter base than a traditional 1970s keel. It releases better out of turns while keeping most of the speed-through-flat-sections feel keels are loved for.

Modern Keel or MR TFX Twin?+

Modern Keel = looser, faster, small-wave. MR TFX = more drive, more hold, wider wave range. Grovelers → Modern Keel. Performance twins → MR TFX.

Can I add a trailer?+

Not with the FCS II Modern Keel set — it's sold as a twin. For twin+1 you'd need to switch to a different template set that includes a stabiliser.