This equation also reveals that the density of the surfboard must be very low. This has been accomplished through the application of physics to design. Old surfboards were made of woods that had a lower density than water so it would float. In order to float the additional mass of the rider, a large area was needed. The resulting board was large, had a considerable mass of its own, and produced a slow ride.
New designs incorporate a fiberglass material that has a very low density.
Because the fiberglass is porous, it is coated with resin which hardens, creating a water tight outer shell. The resulting board has a low density, a low mass and a smaller area needed to float a rider. Today's smaller, lighter surfboards are faster and more maneuverable. Balance Balance is one of the keys to surfing. As a beginner, this concept takes a long time, and quite a few spills, to master, but the physics behind it is simple rotational motion.