The board is a 12'0" Walden Magic Model. Flat rocker. Wide tail. A plank, in the best way. It has a 10.5" centre box and no side boxes.
So we drilled side boxes.
Two 4.5" Futures-style sidebites, set about eight inches up from the tail, toed in a touch. No centre fin. No leash plug. Just the two sidebites and whatever waves showed up.
The session
Chest-high. Glassy. A point break that walls up and gives you something to work with if you're patient. The kind of surf where a single fin usually sings — but we weren't riding a single fin.
The first wave was weird. The tail felt alive in a way that big logs don't normally feel. You expect a log to resist you. To need coaxing. This one moved. Not skatey in the fish sense — more like the whole rail lit up differently when you shifted weight. The back section that usually goes dead on a long board held a bit longer. Not much, but enough to notice.
By the third wave it started to make sense. The twin setup does something interesting on a longer board: it gives you a release point the single doesn't. You can push through a section and the tail squirts a little. On a 12-foot board that squirt is tiny by shortboard standards. But the feedback is completely different. The board talks back.
What surprised us
How much hold there was in steeper sections. Twin fins on a fish go loose fast — that's the appeal. On a 12-footer, the same fins felt more planted. The volume and length of the board dampen the tendency to slide. You get the looseness in the trim, but the board doesn't lose its line. It held angle through some sections that had no business holding.
The other thing: walking. Or not walking, technically. Twin fins moved the sweet spot. Standing further forward than usual felt more stable than expected, because the tail was doing something useful rather than just dragging. You still can't really nose ride it — two 4.5" sidebites aren't going to give you the pivot and hold of a 9.5" D-fin. But the mid-board position felt great. That floaty trim that's part of the long-log thing was still there. Different flavour, same pleasure.
The setup details
We used our Twin Fins | Resin | Futures in the sidebite position. No centre fin. The fins were toed in about 1/8", canted about 6 degrees. Standard template for a twin, nothing exotic.
If you're thinking about this for your own log: most modern longboards don't have side boxes. You'll either need a shaper to add them or go with a board that has them from new. The Walden Magic Model has been available with side boxes as a factory option. Worth asking your local shaper whether they'll add boxes to an existing board — most will.
Want to try twin fins before committing to drilling anything? Start with a mid-length or fish that already has the boxes. The Twin Fin a Log page goes through the why and what to expect.
Worth it?
Yes. Not as a replacement for the single fin, but as a completely different way to ride the same board. One session and it made sense. It's not going to make your noserider work better or your trim faster. It's going to make the same board feel like something else. That's the whole point.
Different is fun. Try the weird thing.