You might not think it, but every bit as much thought and design goes into the hydrodynamics of a surfboard as goes into the aerodynamics of an aeroplane wing. The bottom contours of the board are measured to within a fraction of a degree, then studied to see how water flows underneath them. Yes, surfboards were once literally just planks of wood-usually oak. Then they got fins, to make them more controllable. Then lighter woods started to be used. Then came foam, covered in fibreglass. The three-fin revolution arrived like a ninja star, giving boards more drive and manoeuvrability.
Today, boards are generally made out of polyurethane foam/fiberglass or epoxy foam/epoxy resin. The epoxy is lighter and stronger, but many guys feel it’s too rigid and prefer traditional glass, which may produce a smoother ride. Most often, these boards have a balsa wood stringer that runs down their centre line to add structural integrity, though some boards have parabolic stringers that run down the rails — and some have no stringers at all. In average waves, most of the pros ride boards that are about their height. The trend lately though has been shorter, wider, thicker boards. Surprisingly, the wider, fatter boards can be much faster, because their width helps them get on a plane easier, reducing drag.