Powerboat rooster tail depressor

Abstract

A powerboat with a rooster tail depressor (RTD) includes a hull, a propulsion subassembly on the hull, and a rooster-tail-suppressing subassembly on the hull. The propulsion subassembly propels the hull forwardly, producing a propulsion discharge that extends rearwardly of the stern. The rooster-tail-suppressing subassembly extends rearwardly of the stern over at least a portion of the propulsion discharge where it functions to suppress the formation of a powerboat rooster tail (e.g., for radar signature reduction and increased propulsion efficiency). Various embodiments include one or more of (i) a canopy having a downwardly facing surface that is arched (either curved or faceted), (ii) lift-to-drag ratio enhancing steps in the downwardly facing surface of the canopy, (iii) a rooster-tail-suppressing subassembly configured to enable articulation of the canopy in yaw and in trim, (iv) a skeg for enhancing maneuverability of the boat hull, and (v) a conveniently removable and/or retractable rooster-tail-suppressing subassembly.

What is claimed is: 
     
         1 . A powerboat comprising:
 a hull having a stern;   a propulsion subassembly on the hull that functions as means for propelling the hull forwardly, said propulsion subassembly producing a propulsion discharge that extends rearwardly of the stern when the hull is propelled forwardly by the propulsion subassembly; and   means for suppressing the formation by said propulsion discharge of a powerboat rooster tail, including a rooster-tail-suppressing subassembly on the boat hull that extends rearwardly of the stern and over at least a portion of the propulsion discharge.   
     
     
         2 . A powerboat as recited in  claim 1 , wherein the rooster-tail-suppressing subassembly includes a canopy having a downwardly facing surface extending over at least a portion of said propulsion discharge. 
     
     
         3 . A powerboat as recited in  claim 2 , wherein the downwardly facing surface of the canopy is arched. 
     
     
         4 . A powerboat as recited in  claim 2 , wherein the downwardly facing surface of the canopy is faceted. 
     
     
         5 . A powerboat as recited in  claim 2 , wherein the downwardly facing surface of the canopy is curved. 
     
     
         6 . A powerboat as recited in  claim 2 , wherein the downwardly facing surface of the canopy is arched laterally and longitudinally. 
     
     
         7 . A powerboat as recited in  claim 2 , wherein the rooster-tail-suppressing subassembly includes means for enhancing lift-to-drag ratio, including steps in the downwardly facing surface of the canopy. 
     
     
         8 . A powerboat as recited in  claim 2 , wherein the rooster-tail-suppressing subassembly is configured to enable articulation of the canopy in yaw. 
     
     
         9 . A powerboat as recited in  claim 2 , wherein the rooster-tail-suppressing subassembly is configured to enable articulation of the canopy in trim. 
     
     
         10 . A powerboat as recited in  claim 2 , wherein the rooster-tail-suppressing subassembly includes means for enhancing maneuverability of the boat hull, including an attached skeg.