planing surface

A surfboard's bottom surface; more specifically, the area of the board that planes across the water—a definition that may exclude the last foot or so of the nose section. A board's planing surface is usually made up of some combination of flat area, concavity (single concave or side-by-side double concave), convexity, or vee panels. While post–World War II California board-maker Bob Simmons paid a...