Longboarding is the act of riding on a longboard

Longboard (skateboard)

A longboard is a surfing variant of a skateboard, similar and related to a surfboard or snowboard with wheels. It is used for cruising, downhill racing, slalom racing, sliding, and/or transport. However, most stunts, and the boards themselves are very different from that of a typical skateboard...

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Longboarding is an offshoot of street skating, but, like all board sports, its roots lie in surfing. Developed as a single sport on the west coast in the 1950s, by the 1990s, Longboards and Skateboards branched off into their respective disciplines. With the right setup, a longboard can give the feeling of surfing on hard smooth surfaces. There are a variety of riding styles: downhill, cruising and carving, slalom, dancing, freeriding, vert and sliding.
A longboard generally can be as short or as long as the rider desires; the most popular range is about 36 to 60 inches.