Surfboard foil (not to be confused with foil surfing or foil surfboards), describes the distribution of thickness from the board’s nose to its tail and from the deck to the bottom.
Foil distribution dictates where the surfboard’s wide-point should be and how the other areas of the board taper away from that wide-point.
You can get a good idea of a particular surfboard’s foil by placing it on some racks and looking at it from the side. You’ll likely notice a thinner nose that gradually thickens towards the widest part of the board and then tappers down again out of the tail.
Shapers can play with the distribution of the foil to design a board that better suited for different types of waves and surfing styles.
A properly foiled board translate to good flow and smooth, connected motion on a wave. An improperly foiled board may feel “clunky” or unstable as you try to maneuver and surf.
Surfboard Foil Distribution
Depending on the overall shape and design of the surfboard, the wide-point may be closer to the nose or closer to the tail.
Distribution of the boards foil in relation to the wide-point has a big influence on paddle-power, planing speed, buoyancy and stability, maneuverability and responsiveness, and whether the board is designed for more front-footed or back-footed surfing.
Less thickness in the nose of the board will create less weight up front. This makes for a surfboard that’s easier to turn quickly.
The thickest part of most surfboard is near the center. Positioning the thick point forward or backward will have different effects. A thicker board will feel a little stiffer to turn than a thinner board.
Shapers can play with a board’s tail thickness as well. A thick tail section will help lift the back end out of the water – making it easier to paddle and glide. A thinner tail will give you more control and hold in steeper waves.