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.
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.