Apparatus to reduce skin friction drag on a marine vessel

An apparatus to reduce frictional drag on a planing hull of a marine vessel when underway comprising:

• a sonification plate having a mounting surface for positioning on at least a portion of a wetted area of an aft region of said hull and an acoustic surface for emitting acoustic waves in response to a series of transducers positioned inside said sonification plate opposite said acoustic surface,
• an acoustic signal generator to energize said transducers with a signal to activate said acoustic surface to acoustically generate cavitation bubbles by emitting acoustic waves having an intensity that exceeds tensile strength of water in and about a boundary layer at an interface between the aft region of the hull and said water whereby to reduce wetted area resistance of said hull while underway, and
• wherein components inside said sonification plate are sealed from water exposure when mounted on a submersible portion of the hull of said vessel.

An apparatus to improve efficiency of operation of a planing hull marine vessel by reducing wetted area resistance of a hull thereof while underway, said apparatus comprising:

• an insonification region on a submerged portion of an aft region of said planing hull at which to acoustically generate microcavitation bubbles, and
• an acoustic signal generator to energize said insonification region to acoustically generate microcavitation bubbles within a boundary layer of said submerged region between the hull of said vessel and a medium of water whereby to reduce wetted area resistance of said vessel while underway wherein intensity of acoustic waves imparted to said medium lies in a general range of one to ten watts per square centimeter more or less that is sufficient to break tensile strength of water according to a condition of the medium of water interfacing said hull, whereby to established a desired size and duration of cavitation bubbles and to reduce unnecessary energy consumption in water having excessive nuclei upon which to nucleate cavitation and/or to allow dissipation of cavitation bubbles in time to prevent cavitation damage to components of said vessel.