When we launch a new Balanced Catamaran, we weigh her first. Every time. It’s not a ceremony — it’s a commitment to accountability. Numbers don’t lie, and with Twin Fin, our latest 502 with the full carbon core build, the numbers are telling a very good story.
The Number That Matters: One Ton
The carbon core has saved us just over one ton — more than 2,200 pounds — compared to our previous E-glass internal construction. That’s not a rounding error or a marketing claim. It’s the result of a systematic material change throughout the entire structure of the boat, and it’s the kind of saving that changes what a catamaran can do.
Where Does the Weight Actually Come From?
On our 442s and 482s, the internal structure — bulkheads, partition panels, cabin soles, water tanks, fuel tanks — was built in E-glass. It’s a proven material, but it’s heavy.
With the carbon core, all of that internal structure is now carbon fibre. The stiffness gain is enormous. The mass reduction is real. But it doesn’t stop at swapping one material for another.
We’ve also changed the resin system throughout the hull construction to full vinyl ester resin. Vinyl ester is a stronger resin, and that strength allows for lighter laminate schedules across the board. The result is a hull that’s genuinely stiffer and genuinely lighter — not one at the expense of the other.
Stiffness First, Weight Second
It’s important to understand the sequence here, because it’s easy to assume weight saving is the primary goal. It isn’t. The carbon core was first and foremost about structural rigidity.
What we wanted — and what we achieved — was a stiffer, more rigid interior structure throughout the whole boat. A stiffer boat is a faster boat, a quieter boat, and a more durable boat over the long term. The weight saving is a consequence of doing that properly with the right materials.
That said, one ton is a significant number on a performance catamaran, and it touches everything:
- Performance — a lighter boat accelerates faster, points higher, and sails better in light air
- Load carrying capacity — the weight you save on structure is weight you can put to work: chain, anchors, provisions, gear
- Bridge clearance — relevant for bluewater cruisers navigating canal systems and marina entrances
- Longevity — less structural mass means less stress on the rig and appendages over time
No Compromises on the Interior
This is the part we want to be direct about: the carbon core build does not mean a stripped-out, spartan interior. Our customers sail offshore. They need refrigeration. They need air conditioning. They carry spare anchors and chain. They load boats up — that’s just the reality of bluewater cruising.
Any builder who doesn’t account for that is building to a spec sheet, not to how people actually use boats.
Our cabinetry remains fully custom — handmade, foam-core, beautiful. The doors, the joinery, the fit-out you’d expect from a Balanced Catamaran — all of it is still there. The carbon core and the furniture philosophy work together. Foam-core cabinetry combined with a carbon fibre structural interior is a difficult combination to beat for a performance cruising catamaran built to this standard.
The balance we’re striking is simple: build it as light as we responsibly can, build it as strong as it needs to be, and never remove something a bluewater sailor actually needs.
What It Means for the 464 and 502
The carbon core is standard on both the 464 and the 502. Every panel, every bulkhead, every structural component — carbon fibre throughout, in vinyl ester resin. One ton lighter. No compromises.
Twin Fin is about to go into sea trials, and we’re genuinely excited to see what she does on the water. The build numbers are in. Now we find out what they feel like under sail.
Want the full technical deep-dive? Phil’s factory walkthrough — covering every carbon panel, every structural detail, and exactly how it all fits together — is linked in the description below.
Stay subscribed. There’s a lot more to come from Twin Fin.
