A paddle is a tool used for pushing against liquids, either as a form of propulsion in a boat or as an implement for mixing. Paddles commonly used in canoes consist of a wooden, fibre glass, carbon fibre or metal rod (the shaft) with a handle on one end and a rigid sheet (the blade) on the other end. Paddles for use in kayaks are longer, with a blade on each end; they are handled from the middle of the shaft.