Editing Surfboard (section)

===Rails===
The edges of the board. A rounded rail is called "soft", while a more squared-off rail is called "hard", and rails that are in between are termed "50/50" ("fifty-fifty"). Larger, fuller rails contain a greater volume of foam giving the board increased buoyancy along the edge, while sharper, narrower rails have less volume, making the board easier to "sink" and "lean on edge".  While riding down the line, one rail is always in the water while the other is suspended freely in the air. Turns are largely a matter of transitioning from rail to tail and over to the contralateral (opposing) rail.