Abstract: A powerboat with a rooster tail depressor (RTD) includes a hull, a propulsion subassembly on the hull, and a rooster-tail-suppressing canopy on the stern that includes a downwardly facing surface no less than six inches above the dynamic water line of the stern where it functions to suppress the powerboat rooster tail 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, and (iv) operator-controlled port and starboard venting arrangements on the canopy that result in desired laterally directed thrust for enhanced maneuverability.

Abstract: A model hull testing method, platform, and system are disclosed that acquire model hull performance data about one or more hulls in an open-water environment, preferably testing two hulls simultaneously as they encounter essentially the same sea state. Avoiding tow-tank testing by providing a powered watercraft as an open-water testing platform, the method proceeds by supporting the model hulls on the testing platform, so they float in outboard positions, and then by acquiring data about hull performance as the testing platform and model hulls move together through an open body of water. A complement of data acquisition components acquires digital and analog data about the testing environment and model hull performance, preferably including platform motion, time and location information, wave characteristics, apparent wind speed and direction, and model hull drag and motion, with all data being recorded on an onboard laptop computer for later processing and analysis.

Abstract: A model hull testing method, platform, and system are disclosed that acquire model hull performance data about one or more hulls in an open-water environment, preferably testing two hulls simultaneously as they encounter essentially the same sea state. Avoiding tow-tank testing by providing a powered watercraft as an open-water testing platform, the method proceeds by supporting the model hulls on the testing platform, so they float in outboard positions, and then by acquiring data about hull performance as the testing platform and model hulls move together through an open body of water. A complement of data acquisition components acquires digital and analog data about the testing environment and model hull performance, preferably including platform motion, time and location information, wave characteristics, apparent wind speed and direction, and model hull drag and motion, with all data being recorded on an onboard laptop computer for later processing and analysis.

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).

Abstract: A watercraft with at least one onboard propulsion engine includes at least two hulls and a wing-like deck structure spanning the two hulls (a floating wing). Port and starboard skirts combine with the deck structure to form port and starboard planing channels. The deck structure includes an upwardly facing surface that slopes downwardly toward an aft end of the deck structure in order to provide aerodynamic lift. Preferably, a speed-responsive exhaust proportioning system vents exhaust at vertical steps in planing surfaces on the hulls to reduce drag, increase lift, and reduce thermal signature. One embodiment includes hinged laterally extending deck extensions that an operator can raise to reduce vessel breadth during docking, upwardly extending barriers on the deck extensions that reduce the escape of wind laterally, and hinged flap structures disposed rearwardly that enable an operator to adjust vessel trim.

Abstract: A watercraft with at least one onboard propulsion engine includes at least two hulls and a wing-like deck structure spanning the two hulls (a floating wing). Port and starboard skirts combine with the deck structure to form port and starboard planing channels. The deck structure includes an upwardly facing surface that slopes downwardly toward an aft end of the deck structure in order to provide aerodynamic lift. Preferably, a speed-responsive exhaust proportioning system vents exhaust at vertical steps in planing surfaces on the hulls to reduce drag, increase lift, and reduce thermal signature. One embodiment includes hinged laterally extending deck extensions that an operator can raise to reduce vessel breadth during docking, upwardly extending barriers on the deck extensions that reduce the escape of wind laterally, and hinged flap structures disposed rearwardly that enable an operator to adjust vessel trim.

Abstract: A watercraft with a propulsion engine includes at least one hull having an underside. A dual exhaust system includes a first exhaust conduit defining a first exhaust flow path leading to the underside (e.g., a step in a planing surface on the underside) and a second exhaust conduit defining a second exhaust flow path to atmosphere. One embodiment is self proportioning. In another embodiment, an onboard proportioning system varies first and second proportions of the exhaust flowing through respective ones of the first and second exhaust conduits according to exhaust back pressure. First and second valve mechanisms selectively restrict the first and second exhaust flow paths under computer or manual control according to pressure sensed by a back-pressure-sensing component in order to thereby direct the exhaust in desired proportions for enhanced operating characteristics and reduced thermal signature.

Abstract: A watercraft with a propulsion engine includes at least one hull having an underside. A dual exhaust system includes a first exhaust conduit defining a first exhaust flow path leading to the underside (e.g., a step in a planing surface on the underside) and a second exhaust conduit defining a second exhaust flow path to atmosphere. One embodiment is self proportioning. In another embodiment, an onboard proportioning system varies first and second proportions of the exhaust flowing through respective ones of the first and second exhaust conduits according to exhaust back pressure. First and second valve mechanisms selectively restrict the first and second exhaust flow paths under computer or manual control according to pressure sensed by a back-pressure-sensing component in order to thereby direct the exhaust in desired proportions for enhanced operating characteristics and reduced thermal signature.

Abstract: A watercraft includes at least one hull having at least one planing surface, at least one vertical step in the planing surface, and an onboard propulsion engine. An exhaust-venting system is provided for venting exhaust from the onboard propulsion engine at the vertical step in the planing surface while under way in order to introduce gas along the planing surface. The hull of one embodiment takes the form of an M-shaped boat hull. The invention also applies to any of various other watercraft hulls, including watercraft with multiple hulls such that each of the multiple hulls includes one or more planing surfaces with one or more vertical steps at which exhaust is vented.

Abstract: A watercraft includes at least one hull having at least one planing surface, at least one vertical step in the planing surface, and an onboard propulsion engine. An exhaust-venting system is provided for venting exhaust from the onboard propulsion engine at the vertical step in the planing surface while under way in order to introduce gas along the planing surface. The hull of one embodiment takes the form of an M-shaped boat hull. The invention also applies to any of various other watercraft hulls, including watercraft with multiple hulls such that each of the multiple hulls includes one or more planing surfaces with one or more vertical steps at which exhaust is vented.