Fins have a huge impact on the feel, stability, drive and maneuverability of the board. If you are unsure about the performance of your board, experiment with different fins and different fin setups.
In this guide we will give you some basic information on key terms:
1 FIN AREA
The surface area of all fins combined affect the way the board feels. Lots of surface area provide more control and stability, less surface area give the board more speed but less control. Larger surfers will want a fin with a larger surface.
The length of the bottom of the surf fin that makes contact with the bottom of your surfboard. Fins with a longer base will offer more drive and acceleration. It also affects the turning arc. Fins with a smaller base will have a smaller turning arc.
The distance from the base of the fin to the top of the fin. The more depth the fin has, the more hold and control you will have in your turns.
Also referred to as rake. It is how far the fin curves backward. If a fin has lots of sweep, with more curvature, it will allow you to do longer turning arcs. Less sweep will offer a tighter turning arc.
Flex is how stiff the fin is. If it does not give left or right, your board will be very responsive and fast. A fin with lots of flex will be more forgiving, slower and less responsive.
The foil of a sin describes how aerodynamic a surfboard fin is. A surfboard fin either has a symmetrical or asymmetrical foil. A 50/50 symmetrical foil can be seen on most center fins. A flat foil is flat on the inside and curved on the outside.
The foil has a big impact on the way the water flows under the board. The idea is to create lift under the surfboard and make your board go faster and smoother. The more foil, the more drag on the board which slows it down.