Abstract: A thrust system for a watercraft including a propeller shaft, a propeller shaft housing and a hydraulic thrust bearing assembly. The propeller shaft has an enlarged diameter shoulder, and the housing is positioned around and allows axial movement of the propeller shaft. The hydraulic thrust bearing assembly is axially constrained between the propeller shaft shoulder and the housing. The hydraulic thrust bearing assembly includes an annular cylinder, an annular piston, at least one oil feed passage and at least one oil bleed port. The annular cylinder surrounds the propeller shaft and has a circular groove. The annular piston surrounds the propeller shaft and is movably positioned within the circular groove of the annular cylinder forming a pressurized chamber. Each oil feed passage and oil bleed port allows oil to be communicated relative to the pressurized chamber. The hydraulic pressure developed in the pressurized chamber is proportional to thrust.

Abstract: A quick change bearing holder apparatus for a rotating shaft including a shaft housing, a conical bearing holder and a bearing retainer element. The shaft housing has a conical socket. The conical bearing holder has an outer conical surface compatible with the conical socket of the shaft housing. The bearing retainer element mounts to the shaft housing to urge the bearing holder into the conical socket of the shaft housing. Lubrication feed lines and openings and drain lines and openings may be included in the shaft housing and conical bearing holder. Lubrication may further be facilitated using circumferential grooves in the shaft housing or the conical bearing holder. The outer conical surface of the conical bearing holder may have a taper angle that forms a self ejecting taper.

Abstract: A thrust system for a watercraft including a propeller shaft, a propeller shaft housing and a hydraulic thrust bearing assembly. The propeller shaft has an enlarged diameter shoulder, and the housing is positioned around and allows axial movement of the propeller shaft. The hydraulic thrust bearing assembly is axially constrained between the propeller shaft shoulder and the housing. The hydraulic thrust bearing assembly includes an annular cylinder, an annular piston, at least one oil feed passage and at least one oil bleed port. The annular cylinder surrounds the propeller shaft and has a circular groove. The annular piston surrounds the propeller shaft and is movably positioned within the circular groove of the annular cylinder forming a pressurized chamber. Each oil feed passage and oil bleed port allows oil to be communicated relative to the pressurized chamber. The hydraulic pressure developed in the pressurized chamber is proportional to thrust.

Abstract: A quick change bearing holder apparatus for a rotating shaft including a shaft housing, a conical bearing holder and a bearing retainer element. The shaft housing has a conical socket. The conical bearing holder has an outer conical surface compatible with the conical socket of the shaft housing. The bearing retainer element mounts to the shaft housing to urge the bearing holder into the conical socket of the shaft housing. Lubrication feed lines and openings and drain lines and openings may be included in the shaft housing and conical bearing holder. Lubrication may further be facilitated using circumferential grooves in the shaft housing or the conical bearing holder. The outer conical surface of the conical bearing holder may have a taper angle that forms a self ejecting taper.

Abstract: A water flow limiting system for a boat including a water flow limiting plate, a coupling mechanism and a controllable bite ram. The water flow limiting plate is positioned below the propeller shaft and forward of the propeller for limiting water flow to the propeller. The coupling mechanism is provided for steering the water flow limiting plate relative to the boat. The coupling mechanism may be a mounting mechanism which maintains the flow limiting plate generally aligned with the propeller shaft, or it may be a steering mechanism which steers the flow limiting plate relative to the propeller shaft. The controllable bite ram controls vertical displacement of the flow limiting plate relative to the propeller shaft. A propeller guard system positioned above the water flow limiting plate may be included. A cooling coil may be affixed to the water flow limiting plate.

Abstract: A gimbal assembly for a watercraft propeller propulsion system including first and second generally cylindrical gimbal ends each having a pair of diametrically opposing gimbal yokes, and an external gimbal ring pivotally coupled to the opposing gimbal yokes of each of the first and second gimbal ends. The gimbal ring may include a zigzag shaped gimbal ring body with opposing extensions orthogonal to opposing depressions and corresponding pairs of opposing gimbal pin couplings. The opposing gimbal yokes of each gimbal end may include opposing gimbal pin couplings for coupling to the couplings of the gimbal ring. Each gimbal end may be assembled through one face of the gimbal ring and internally coupled to pin couplings of an opposite face of the gimbal ring. The gimbal pins may be clamped with U-bolts. The opposing gimbal yokes may have minimal clearance around a universal joint. A bellows may be mounted externally.

Abstract: A docking light system for a watercraft including a docking light fixture, a docking lamp positioned within the docking light fixture, and an accessory lamp mounted to the docking light fixture. The accessory lamp emits light outwardly from the watercraft and is masked to control the horizontal and vertical beam spread sectors of emitted light from illuminating the watercraft causing glare to an occupant of the watercraft. In another aspect, a navigation light is provided on the docking light fixture, where the navigation light may be a masthead light, a stern light, a port side marker light, a starboard side marker light, etc.

Abstract: A thrust bucket for use on a boat propeller including a plenum and a positioning system. The plenum includes a plenum wall with at least one water flow valve located on the plenum wall. The positioning system moves the plenum between inoperative and operative positions. The thrust bucket may include an annulus positioned in close proximity to a swept radius of the propeller when the plenum is in the operative position. The at least one operable water flow valve may be controlled to control a direction of water departing the plenum, or to control a quantity of water flow out of the plenum. The thrust bucket may further include a propeller guard mounted to the plenum and positioned at an inlet side of the propeller.

Abstract: A water flow limiting system for a boat with a propeller shaft and a propeller including a water flow limiting plane and a mechanism. The water flow limiting plane is provided for positioning below the propeller shaft and forward of the propeller for limiting water flow to the propeller. The mechanism is provided for steering the water flow limiting plane relative to the boat. If the propeller shaft is steerable relative to the boat, the mechanism may be a mounting mechanism which maintains the flow limiting plane generally aligned with the propeller shaft. The mechanism may be a steering mechanism which steers the flow limiting plane relative to the propeller shaft. A bite ram may be included for controlling vertical displacement of the flow limiting plane relative to the propeller shaft. The mechanism may be a mounting mechanism for mounting the flow limiting plane to a propeller shaft carrier.

Abstract: A navigation light system for a watercraft including multiple lights of a common color and that are spatially separated on the watercraft to collectively operate as a navigation running light that has a specified horizontal beam sector of less than 360 degrees. Each light is separately masked to emit light outwardly from the watercraft within a partial arc horizontal beam sector which is less than the specified horizontal beam sector. The navigation light system may include first and second running lights of first and second colors, respectively, where each running light includes multiple commonly-colored lights that are separately masked within a corresponding one of mutually exclusive partial arc horizontal beam sectors within the specified horizontal beam sector.

Abstract: A variable area trim tab which is adjustable to control its effective area of the trim tab for use on boats having any of several propulsion methods. Area control is used to vary the effective lift area of the trim tab and to control the water flowing to, or flooding, the propeller. Flood doors and flood gates may be water blocking style, or water passing style to control water flow to the propeller. Area control and flood control components are also used as propeller guards, or propeller screens. Tunnel propellers use sliding and hinged tunnel closures to control water flow to the propeller. Sliding closures serve as propeller guards when the propeller is in the raised position. Side inlet water flow pipes allow water to fill propeller tunnels and serve as a side thruster propeller housing.

Abstract: A propulsion system for a boat including a drive system and a propeller positioning system. The drive system may be of any type, such as outboard motors, inboard/outboard drives, surface drives, etc. The positioning system constrains movement of the propeller shaft to swing in a path generally parallel to the bottom surface of the boat. The boat has a hull with either a flat or a sloped bottom surface. Various positioning systems include bite bars, bite rams, cambered drives, jack boxes, jack plates and various linkage configurations. In one aspect a tie bar links multiple drives together. In another aspect, a four-bar steering linkage enables variations in immersion depths of multiple propellers while maintaining constant toe-in. In yet another aspect, yaw steering is achieved using differential immersion between multiple propellers.

Abstract: A trim tab shape control system for a boat with a transom according to an embodiment of the present invention includes a flexible plate and a trim tab control system. The flexible plate has a forward end attached to the transom, a rearward end, and an operative bottom surface. The trim tab control system includes a first force mechanism that is attached near the rearward end of the flexible plate and at least one second force mechanism interfacing the flexible plate between the transom and the first force mechanism. The force mechanisms are operative to deflect the operative bottom surface of the flexible plate in a controlled curve while in an up position, where the plate retains a shape in a down position which varies with force applied by the first and second force mechanisms and the operating conditions of the boat.

Abstract: A trim tab of resilient material affixed in a cantilever fashion at the stem of a boat and of a regressive flexural stiffness such that when deflected, the undersurface of the trim tab assumes the shape of a progressive curve in the direction of water flow. A trim tab of a progressive curve which has gas or liquid ejection to the undersurface to control the boundary layer. A trim tab located under a surface drive whereby the bite of the propeller is controlled relative to the trim tab and the trim tab is controlled to optimize the boat hull.

Abstract: A navigation light system for a watercraft including an accessory light located at the bow or the stern that operates as a masthead or stern light, respectively, and that is located relative to the hull perimeter and shear line of the hull to reduce the glare perceived by an occupant of the watercraft. The glare is further reduced by the use of suitable masks to control the horizontal and vertical beam spread sectors of emitted light to minimize glare as perceived by an occupant of the watercraft. A docking light system that includes an accessory lamp that may be operated as a masthead light or as a stern light which is positioned to reduce glare as perceived by an operator of the watercraft and to increase visibility to other watercraft.

Abstract: A navigation light system for a watercraft including an accessory light located at the bow or the stern that operates as a masthead or stern light, respectively, and that is located relative to the hull perimeter and shear line of the hull to reduce the glare perceived by an occupant of the watercraft. The glare is further reduced by the use of suitable masks to control the horizontal and vertical beam spread sectors of emitted light to minimize glare as perceived by an occupant of the watercraft. The accessory light may include a fiber optic to an annunciator panel. The accessory light may be mounted to an appurtenance, such as a railing or pulpit or the like. An adjustable eyeball light fixture that serves as the accessory light. A docking light modified to include an accessory lamp for operating as a masthead or stern light.

Abstract: A trim tab of resilient material affixed in a cantilever fashion at the stern of a boat and of a regressive flexural stiffness such that when deflected, the undersurface of the trim tab assumes the shape of a progressive curve in the direction of water flow. A trim tab of a progressive curve which has gas or liquid ejection to the undersurface to control the boundary layer. A trim tab located under a surface drive whereby the bite of the propeller is controlled relative to the trim tab and the trim tab is controlled to optimize the boat hull.

Abstract: A navigation light system for a watercraft including an accessory light located at the bow or the stern that operates as a masthead or stern light, respectively, and that is located relative to the hull perimeter and shear line of the hull to reduce the glare perceived by an occupant of the watercraft. The glare is further reduced by the use of suitable masks to control the horizontal and vertical beam spread sectors of emitted light to minimize glare as perceived by an occupant of the watercraft. The accessory light may include a fiber optic to an annunciator panel. The accessory light may be mounted to an appurtenance, such as a railing or pulpit or the like. An adjustable eyeball light fixture that serves as the accessory light. A docking light modified to include an accessory lamp for operating as a masthead or stern light.