The location of the widest point of the board's outline affects the performance of the surfboard. There are three basic outlines that are commonly shaped in all types of surfboard lengths and designs.
1. Wide point back
2. Wide point center (paralleled rail design)
3. Wide point forward
A surfboard's outline can be looked at in two halves, the front half provides speed, grip, and stability when we engage the rail of the surfboard into the wave face.The rear half of the board provides maneuverability and responsiveness when we lean our weight onto the tail and lift the nose higher out of the water to disengage the rail from the way face and pivot off the back foot to change direction.
The widest point of the board is going to loosely define where the divide between those two control surfaces are and how the overall speed and grip or maneuverability and responsiveness are either increased or decreased. Keep in mind the wide point is not necessarily the midpoint of the outline and how the shape affects how the board will perform.
Wide point Back from Midpoint
Let's start at the rear with wide point back behind the surfboard's midpoint. Pulling the wide point of the surfboard back increases the amount of curve through the back half of the outline making the board easier to carve through turns by narrowing the nose and reducing the material and weight up front. The swing weight of the board through a maneuver is reduced and makes the board more responsive. By eliminating the width of the nose it reduces the risk of catching the outside rail and so helps surfing closer to the curl in steeper waves or in tubes.
Wide point Centered at Midpoint
As we move the wide point further forward closer to the midpoint of the surfboard we end up with a more balanced outline where the nose and tail are closer in width and as the nose width increases so does the stability of the surfboard. When in trim creating more surface area to provide lift and thrust becomes particularly useful in either soft waves or when nose riding a longboard when speed and grip are particularly important. This is probably the most common outline we see in modern longboards and fish as it gives a nice balance between maneuverability and stability
Wide point Forward of Midpoint
An outline that has pushed the widest part of the board forward of the midpoint further increases lift and stability in the front half of the board. Wide point forward is typical of noserider longboards and useful on soft waves with little to no steep face to engage the rail earlier and crate lift and stability for nose riding. The tail of the board is narrower which aids in turning and maneuvering the board.