A springboard or diving board is used for diving and is a board that is itself a spring, i.e. a linear flex-spring, of the cantilever type.
Springboards are commonly fixed by a hinge at one end (so they can be flipped up when not in use), and the other end usually hangs over a swimming pool, with a point midway between the hinge and the end resting on an adjustable fulcrum.
Read more about Springboard: Springboard Materials, Adjustment of The Spring Constant, Counter-intuitive User-interface, Heights of Springboards, Home Springboards