Duo | Mid Mk.6: six versions of a mid length twin fin
The 6'4" Mk.6 is the sixth version of our Duo | Mid. The published numbers show where the model went, and who it suited.
The Duo | Mid was our mid length twin: an easy paddling, early catching board with a refined nose that let you take off deeper, for waves from about 1ft to 6ft and surfers from beginner to advanced. In April 2026 Joe posted its sixth version, the Mk.6, with a one-line introduction: “Latest mid length. The Duo | Mid evolution Mk.6.” It measured 6'4" x 19 9/16" x 2 3/8" and held 32.1 litres.
Where the Duo | Mid comes from
The Duo | Mid grew out of the Rose | Mid, our first mid-length. The Rose had the contours of a scaled-down longboard with the rails and tail of a small wave board, the board you took out when your arms were tired and the lineup was busy.
The Duo | Mid keeps that paddle and glide and sharpens the front end. A refined nose outline lets you take off deeper and roll onto the rail more easily. The intent is one board for beach breaks, reefs and points.
Joe has been working on it in the open for a while. In January 2025, at the Burleigh Heads factory, he posted from the shaping bay that he was “designing my newest Duo-Mid model.” The same month he made one for himself: 6'4" x 20" x 2 1/4", with a black stringer and glossed logos.
The numbers, side by side
Here are the Duo | Mids Joe has published dimensions for, in the order he posted them.
| Board | Posted | Length | Width | Thickness |
|---|---|---|---|---|
| Custom, dark blue tint | January 2025 | 6'6" | 20" | 2 1/2" |
| Custom, aqua tint | January 2025 | 6'6" | 20" | 2 1/2" |
| Joe’s own, black stringer | January 2025 | 6'4" | 20" | 2 1/4" |
| Custom, Burleigh Heads factory | July 2025 | 6'4" | 20" | 2 1/2" |
| Mk.6 | April 2026 | 6'4" | 19 9/16" | 2 3/8" |
Three things stand out.
- The length has settled. The last three are 6'4". For a lot of surfers that is the size where a mid-length still fits in the car and still turns off the tail, and it is where this model seems most at home.
- The width has come in. Every earlier board was an even 20 inches. The Mk.6 is 19 9/16", a little under half an inch narrower. On a board this length that is a real change. A narrower board goes from rail to rail faster and holds better when the wave has some push.
- The thickness has found a middle. Earlier boards were either 2 1/4" or 2 1/2". The Mk.6 sits between them at 2 3/8". With the width trimmed, the foam has been kept where it helps you paddle.
The result is 32.1 litres in a 6'4". We publish that figure because volume is the number most people compare, but it only means something next to the surfer. This board was shaped for one rider. The same model for someone heavier, or someone newer to surfing, would be drawn with more width and more foam, and it would still be a Duo | Mid. If you want a starting number for yourself, try the volume calculator, then bring it to the consultation.
Why keep changing a board that works
A model here is a starting outline: a set of curves Joe knows well, which he then adjusts for the person ordering. Every one of those orders teaches him something about where the board works and where it could be better.
That is the idea behind a design and development team. The surfers Joe works with ride the boards hard, say what they feel, and the next one changes. The Mk.6 is where that has got to so far. We would be surprised if it is the last. There is more on how Joe keeps refining his outlines on the know-how page.
It is the same thinking that goes into every custom. When Junkyard Surf asked Joe what he hopes someone feels the first time they ride one of his boards, his answer was:
“I want it to feel like their board.”
The details on this one
Graphics on the Mk.6 are by Rhema Graphics, who Joe thanks for “always supplying me with the highest quality graphics”. The post closes with a line he added under the credits: “Study the folds, not the faces.”
Like every board we build, it was shaped, glassed and finished by hand in house, and it went out with grub screws and a leash rope.
Who the Duo | Mid suited
It suited surfers who wanted one board for most days, liked to take off a little deeper than a classic egg allows, and wanted to turn it properly once up. It was a good step for a shortboarder after more waves without giving up performance, and for a longboarder who wanted something that fits in the pocket.
The Duo | Mid is a past build. Our current mid-length is the Asym | Mid, a board built around your stance; it is on the mid-length page, and we compare the wider families in fish, mid-length or longboard. The twin fin side of it is covered in twin fin surfboards, explained.
The Asym | Mid starts from $1,400. Colour, inlays and finish are chosen with the board, and it takes 4 to 6 weeks.
