Patent ID: 8696318
Filing Date: 2014-04-15
Classification: B63H,F03B

Abstract:
1. A blade of a surface piercing propeller for a marine craft comprising: a blade root securably attached to a propeller hub; a blade tip distal to the blade root; a blade face and an opposing blade back; a tapered leading edge and an opposing trailing edge; a trailing edge step feature on the blade face; and at least one geometric feature on either the blade back, the blade face, or both, that is located between approximately twenty percent and eighty percent of a blade chord length; wherein the trailing edge step feature rises from a local surface of the blade face when traversing the blade face from leading edge to trailing edge; and wherein the trailing edge step feature further comprises at least one region of increasing slope when traversing a surface of the blade from leading edge to trailing edge whereby a fluid pressure peak is created substantially at or near the region of increasing slope during a rotation of the blade in a fluid.