A rudder is a broad, flat piece of wood, attached to the stern of a ship and used to steer it. It’s a period charge, used as a badge by Willoughby, Lord Broke, c.1520 [HCE xxxiv]. The rudder has its hinge to dexter by default; it is usually, though not invariably, shown with its tiller.
Maria Corva bears: Quarterly azure and vert, a rudder Or.
Raymond Carder the Sea Rover bears as a badge: On a rudder purpure, an equal-armed Celtic cross saltirewise Or.