A bodyboard, known in surfing slang as a 'sponge', is a form of surfboard consisting of a small roughly rectangular piece of foam, shaped to a hydrodynamic form. The bodyboard is ridden in a similar way to the better known surfboard, but is predominately ridden lying down, (or 'prone'). It can also be ridden in a half-standing stance (known as 'dropknee') or can even be ridden standing up.
The vast majority of bodyboarders usually wear swimfins on both feet to aid in paddling out and taking off. The bodyboard differs from a surfboard in that it is much shorter. Typically they are 42 inches in length, with a squared off nose and angular rails. They are designed to be flexible, and bodyboarders as a whole are more experimental with various materials than their stand-up cousins. The board is made up of a 'core', made from polyproylene, dow, or arcel. These are types of plastic, and each gives a bodyboard a different amount of flex and control for the rider. Glued to this core is a thick plastic bottom (known as the 'slick') which gives the board strength and speed. The top of the board (the deck) is made from softer plastic to give grip and cushioning to the rider. Unlike a surfboard, there is no fin or skegs allowing the rider to rotate the board. But, like the surfboard, a bodyboard can be made with a stringer (or two) to further increase its stiffness. If one so desires, a skeg can be purchased and installed in about 1 minute. A skeg can minimize the looseness that is required for many tricks. This has led to a large decrease in the presence of skegs.
Although bodyboarding is seen as surfing's easier cousin, beyond the beginner level they are equal in the time and dedication it takes to become proficent. The sport differs somewhat in attitude. Bodyboarding is far more trick-orientated than surfing, and there are hundreds of variations of manouvre possible. Bodyboarders regularly go for 'lip moves' which involve riding up to the lip of the wave with as much speed as possible, and then taking to the air and performing very gymnastic maneuouvres high above the surface, before slamming back down.
Bodyboarding is arguably the earliest form of surfing, and is ultimately derived from the ancient Hawaiian Paipo board, which was ridden lying down. The modern invention of the bodyboard is credited to Tom Morey, who sold very basic bodyboards, (known then as Boogie Boards) by mail order. They were very crude by today's standard, but were easy to ride and became popular.