A spoon is a fully flexible kneeboard, invented and developed by George Greenough circa 1964. They don't paddle well, only carrying about 10 lbs. before sinking. They aren't wide or long, so they don't ride weak surf. Therefore they aren't very popular.

But! being the only fully flexible surfboard, they can tap the juice and fit the required radius better than anything else on the water, bar none. So the spoon rider quickly becomes the dedicated spoon freak.
"BOUT A SPOONFUL" -- Bob McTavish