2+1 Fins

A 2+1 is a center single fin (in a standard US box) flanked by two smaller side fins (in FCS or Futures plugs). The center fin does the heavy lifting — setting the board's character, drive, and turning radius. The side fins engage when you put the board on rail, creating drive down the line. One key Swaylocks tip: downsize your center fin by at least one inch when adding side bites — running the same big single with sides creates too much drag.

The beauty of 2+1 is versatility. You can ride the center fin alone for a pure single-fin feel, or add the sides when conditions get steeper. As Swaylocks puts it: the thruster "doesn't work all that well on boards over 8', as it forces you to surf off the tail too much" — the 2+1 solves this, letting you trim from the middle and still carve when you step back.

Matching your center fin to your sides matters. A large center with small sides feels mostly like a single fin with extra hold. Standard placement: side bite trailing edges about 1" forward of the center fin's leading edge, 3.25" sides with a 6.5"–7.5" center. Combo sets (center + matched sides from the same designer) take the guesswork out.