If you go to a beach in the continental united states and you are standing on a long, flat strand of sand, and you look away from the open ocean and see only a few low sand dunes and then a large, open waterway, where are you?

If you are in this kind of geographical scenery, you must be on a surfing beach in California. The Californian coastline is characterized by a numerous number of beaches that are mainly sandy and features major rivers such as the Sacramento River and the Colorado River.

That would be kinetic energy