Surfboard rudder-fin combination

摘要

A surfboard steered by a fin that functions as a rudder in response to force due to gravity of surfer's body. A vertical shaft connects the rudder-fin to the surfboard body. Its fixed space relationship in respect to the rudder-fin divides the lateral surface of the rudder-fin into two portions of unequal sizes. The shaft is rotatably mounted in the body of the surfboard. A lever arm adjustable in length is provided between the shaft and body to vary steerability characteristics.