This design was created back in 70s when shapers were trying different fin set ups to increase manoeuvrability compared to the classic single fins that everyone was riding. The theory behind this is by having a smaller centre fin and 2 glassed on side fins for stability and control. The specific angle of the side fins hit 90degrees to the waters surface during rail to rail transition, providing maximum control. The outside fin, on the other hand, deflects water down and back through the tail, creating a more efficient water flow under the board, thus increasing speed.
A very unique board that has its own line to draw. Best ridden in waves that have a bit more power.
Rocker: low entry and exit rocker
Concave: A double concave within a single channel on a single concave