Surfboards are sports equipment that people use for surfing. The surfboard originally used was about 5 meters long and weighed 50-60 kilograms. After the Second World War, foamed plastic boards appeared, and their shapes were also improved. The current surfboard is 1.5~2.7 meters long, 60 centimeters wide and 7~10 centimeters thick. It is light and flat, and its front and rear ends are slightly narrow. There is a tail fin at the bottom of the back that acts as a stabilizer. In order to increase friction, a waxy outer film is also coated on the board surface.