Abstract: A stand-up type personal watercraft is disclosed. The stand-up type personal watercraft typically includes a body including a hull and a deck covering the hull from above and being provided with a foot deck on an upper surface of a rear portion thereof to allow a rider to ride thereon, a handle pole configured to extend rearward in a longitudinal direction of the body, the handle pole having a steering handle attached to a rear end portion thereof, the handle pole being configured to be mounted to the deck such that a front end portion of the handle pole is attached to a front portion of the deck and the handle pole is vertically pivotable around the front end portion thereof, and a display device mounted to the handle pole and configured to display information regarding the watercraft.

Abstract: A water jet propulsion watercraft that allows accurate speed detection of a speed detection unit to be achieved. A water jet propulsion watercraft includes a hull bottom plate with left and right guide grooves for guiding water rearwardly of the hull. The left and right guide grooves are disposed in a fore-and-aft direction at an area excluding at least a front portion of the hull bottom plate. Further, the hull bottom plate includes a flat surface formed at the front portion of the left and right guide grooves and on a surface facing the water. The flat surface is provided with an opening for guiding water to a speed detection unit.

Abstract: A haptic throttle control mechanism includes a vibrating element that is connected in vibration transmitting relation with the control mechanism. The vibrating element can be a motor with an eccentric weight attached to its shaft or a piezoceramic component. The vibrating signal can be used to provide information to the operator of the marine vessel relating to the actual operating speed of the engine or, alternatively, it can be used to alert the operator of an alarm condition.

Abstract: In one embodiment, a vehicular collision avoidance method is provided that includes monitoring a control of a vehicle and activating a first alarm if the control is not adjusted in a sufficient amount of time. The monitored control is normally and regularly adjusted by the vehicle's operator such that the time between adjustments is sufficiently smaller than the time normally needed to avoid a collision after it is detected that the control is no longer being controlled. The first alarm is activated if it is determined that the control is not adjusted in a sufficiently small amount of time from its preceding adjustment. Thus, the vehicle's operator or other vehicle member can react and take measures to ensure that the vehicle is under suitable control upon activation of the alarm and thereby avoid a possible collision.

Abstract: A trim angle correction indicating system for an outboard motor indicates the trim angle of an outboard motor accurately even when misalignment of a detector and deviation in detection value occur. A detector detects the trim angle of an outboard motor, and a trim angle indicating section indicates the trim angle detected by the detector. An offset value setting section sets the detection value detected by the detector when the outboard motor is at a reference position as an offset value. A correction processing section corrects the detection value detected by the detector based on the offset value set by the offset value setting section. The trim angle of the outboard motor is indicated in the trim angle indicating section based on the correction value provided by the correction processing section.

Abstract: An internal combustion engine comprising an engine body. A combustion chamber is formed in the engine body and has at least one valve seat. A valve is configured to move between an open position and a closed position of the valve seat. A valve actuator is configured to actuate the valve. A variable valve timing mechanism is configured to change an actuating timing of the valve actuator at which the valve actuator actuates the valve. At least one sensor configured to sense and operational condition of the engine. A control device is configured to determine if the engine is operating in a cruising mode. The control device is also configured to reduce engine speed fluctuations during the cruising mode by adjusting the actuating timing of the valve actuator.

Abstract: A device for rotating with a rotatable first member includes a second member having a portion engageable with the first member. The portion has a first part and a second part which is resiliently biased away from the first part. The second member tightly engages the first member. There may be a device for measuring rotation of the shaft such as a potentiometer. The rotation measuring device may include an electrical connector for the potentiometer including a socket and a post which is pressable into the socket. The device may also include a rotationally adjustable connector. There may be a coupling connected to the second member which includes a third member with a portion having n sides and a fourth member with a portion having n sides which receives the portion of the third member in a mating relationship, thereby allowing the device to be adjusted to a total of at least m.n rotational positions.

Abstract: A method and device for processing self-diagnostic information relating to an operating state of a jet-propulsion personal watercraft to display the self-diagnostic information on a display device equipped in the personal watercraft.

Abstract: A vehicle can have plural propulsion devices, at least two of which include number setting sections and number transmitting/receiving sections for transmitting their identification number and receiving identification numbers of the other propulsion devices over a network. When the number transmitting/receiving sections do not receive an identification number of another propulsion device from the network for a predetermined period of time, an initial value preset in the number setting sections is set as the identification number of the propulsion device in the number setting sections. When the number transmitting/receiving sections receive an identification number of another propulsion device from the network, an identification number different from the identification number of the other propulsion device is set in the number setting sections.

Abstract: An operational condition of an outboard motor 1 is detected by an ECU 29, and transmitted via a communication unit 228, from a communication apparatus 283 to a base station 30. Antennas 32 and a cable 33 are arranged along an inner surface of an engine cover 12. The cable 33 is provided with a connector 34 for connecting the antenna 32 to a communication unit 28 and a GPS receiving circuit 31. The communication apparatus and the antennas are held floating in a case 351 which is filled with a gel, and the case 351 is fixed to the engine cover 12. A communication unit 28 is provided inside an engine cover 12. A housing portion 41 for a portable phone PH is provided pivoted about the cover 12 in such a manner that the portable phone is removable from the housing portion 41.

Abstract: A personal watercraft comprises an engine, a sensor configured to detect an operating state of the engine, a control device configured to control an operation of the engine based on a detection signal from the sensor, and a display device including a first display portion configured to output a state of the watercraft based on data output from the control device, wherein the display device includes a storage portion configured to store the data output from the control device.

Abstract: The present invention provides a lighting system for illuminating the interior of a trolling boat wherein the light is attached to or contained within the trolling motor assembly. The invention comprises in one form thereof, a trolling motor assembly having a motor control compartment, a shaft and a motor/propeller assembly. The motor control compartment further comprises a light assembly attached thereto. In a particular embodiment of the invention the light assembly is fixedly attached to the motor control compartment as to provide a lighting means for the interior of the boat. A further embodiment is contemplated wherein the lighting means is contained within the motor compartment and portion of the motor compartment housing is the appropriate material to permit the passage of light through the motor compartment.

Abstract: A process is provided by which the operator of a marine vessel can invoke the operation of a computer program that investigates various alternatives that can improve the range of the marine vessel. The distance between the current location of the marine vessel and a desired waypoint is determined and compared to a range of the marine vessel which is determined as a function of available fuel, vessel speed, fuel usage rate, and engine speed. The computer program investigates the results that would be achieved, theoretically, from a change in engine speed. Both increases and decreases in engine speed are reviewed and additional theoretical ranges are calculated as a function of those new engine speeds. The operator of the marine vessel is informed when an advantageous change in engine speed is determined.

Abstract: A network system using a LAN to provide relative position data for a engine in a plurality of outboard motors attached to a watercraft and using that data to display engine condition information for each engine in the array of engines installed on the watercraft.

Abstract: A jet propulsion watercraft is provided with a multifunctional display portion that displays operating information and various types of warning conditions. Operation switches operate a content displayed in the multifunctional display portion. A fuel injection system injects fuel for a driving source. A warning mark warns of a faulty condition developing in the fuel injection system. Functions are provided that cause the warning mark to light steadily or flash off and on and that indicate a faulty symptom by means of a flashing pattern of a warning lamp (for example, the warning lamp flashes off and on once, twice, three time, or the like) given when the operation switches are operated while the warning mark is lit steadily or flashing off and on. A prompt action can be taken against a malfunction of the fuel injection system. As a result, convenience in eliminating malfunctions of the fuel injection system can be enhanced.

Abstract: A device for rotating with a rotatable first member includes a second member having a portion engageable with the first member. The portion has a first part and a second part which is resiliently biased away from the first part. The second member tightly engages the first member. There may be a device for measuring rotation of the shaft such as a potentiometer. The rotation measuring device may include an electrical connector for the potentiometer including a socket and a post which is pressable into the socket. The device may also include a rotationally adjustable connector. There may be a coupling connected to the second member which includes a third member with a portion having n sides and a fourth member with a portion having n sides which receives the portion of the third member in a mating relationship, thereby allowing the device to be adjusted to a total of at least m.n rotational positions.

Abstract: A watercraft is equipped with an outboard motor and an inboard local area network (LAN) that communicates control signals to the outboard motor. An outboard motor operating device retains the ability to operate the outboard motor even if part of the inboard LAN develops an abnormality. In particular, a control signal that controls the outboard motor and a conditional information signal that indicates a condition of the watercraft are transmitted by independent cables that are mutually separated. Even if the cable for transmitting the conditional information signal or equipment connected to the cable develops an abnormality, transmission of the control signal for controlling the outboard motor is not hindered since the control signal is on the other cable, which is not affected by the abnormality. The conditional information signals are processed to generate and display return-to-port warnings based on the watercraft conditions and other operator issued constraints.

Abstract: The integrated and self contained diesel hydraulic thruster system integral has a dynamic positioning control system for dynamic positioning of any waterborne vessel having a hull with at least two sides and a deck connecting the sides, at least two removably mounted azimuthing thrusters, at least two self-contained diesel hydraulic power units removably secured to the deck, one for each thruster, at least one dynamic positioning computer connected to each of the self contained diesel hydraulic power units, at least one motion reference sensor connected to the dynamic positioning computer to correct reference position signals for motion of the vessel, at least one heading sensor, and at least one sensor that is either a position reference sensor connected to the dynamic positioning computer, an environmental sensor connected to the dynamic positioning computer, or a combination thereof.

Abstract: A personal watercraft comprises an engine, a sensor configured to detect an operating state of the engine, a control device configured to control an operation of the engine based on a detection signal from the sensor, and a display device including a first display portion configured to output a state of the watercraft based on data output from the control device, wherein the display device includes a storage portion configured to store the data output from the control device.

Abstract: In a small boat equipped with a display panel (liquid crystal device) displaying operation information and a change-over switch (set switch) capable of switching from a normal operation in which output of an engine is not limited to a limited operation in which the output of the engine is limited low, the display panel has a display lamp (limit mode display mark) for lighting when switched to the limited operation. Since there is provided a display lamp for lighting when switched to the limited operation for a small boat capable of switching from a normal operation in which output of an engine is not limited to a limited operation in which the output of the engine is limited low, the convenience can be afforded to the operator.

Abstract: An outboard motor position responsive system is disclosed that warns and/or prevents a powerboat operator from engaging the ignition system of an outboard motor when the outboard motor is tilted up beyond a maximum safe tilt position. The system comprises an outboard motor position sensor that is in communication with an ignition switch, wherein the sensor activates an alarm and/or an ignition disabling switch when an operator attempts to engage the ignition system when the outboard motor is tilted up beyond the maximum safe tilt position. An interval-on relay is also provided that limits the amount of time that the alarm and/or the ignition disabling switch are activated. The interval-on relay further prevents against wave-induced alarms with certain types of outboard motor position sensors in accordance with the present invention. A device is also provided that is easily retrofittable with the existing ignition system of a powerboat.

Abstract: An engine for a marine drive has a combustion chamber. An engine body of the engine defines an air intake port communicating with the combustion chamber. An air induction system communicates with the air intake port to introduce air to the combustion chamber through the air intake port. An exhaust system communicates with the combustion chamber through an exhaust port. Intake and exhaust valves move between an opening position and a closing position of the intake port and the exhaust port, respectively. Intake and exhaust camshafts actuate the intake valve and the exhaust valve, respectively. A VVT mechanism is associated with at least one of the camshafts and changes an actuating timing of the camshaft. The VVT mechanism includes a solenoid actuator that varies a hydraulic flow in the VVT mechanisms to change the actuating timing of the camshaft. The solenoid actuator can be operated to receive electric power from a power source. An ECU controls the solenoid actuator based upon a control characteristic.

Abstract: A system for detecting overheat of an internal combustion engine for an outboard motor. In the system,when an elapsed time since engine staring is within a predetermined time, a detected engine temperature is equal to or greater than a first predetermined temperature and an detected engine speed exceeds an idling speed; a threshold value (compared with the detected engine temperature to determine the engine overheating) is changed to be increased. With this, even if the detected engine temperature is higher than a true or actual temperature at, for example, a high engine load immediately after engine starting or when the engine has been left in the idling state, the system can prevent it from being determined unnecessarily as the overheated condition.

Abstract: To provide a speed detecting device mounting structure for a vessel in which a paddle is prevented from being entangled with rubbish and seaweed in the sea, and the paddle is prevented from being damaged or picking-up mud or the like from the sea bottom. In a vessel, a water jet pump is provided at a rear portion thereof. A ship bottom plate is provided below the water jet pump. A speed detecting device is mounted on the ship bottom plate. A paddle of the speed detecting device detects the flow rate of water flow and obtains the propelling speed of the vessel. The speed detecting device mounting structure for a vessel is constructed in such a manner that the paddle of the speed detecting device is disposed on the upper surface of the ship bottom plate, an opening is formed at the portion of the ship bottom plate forwardly of the speed detecting device, and water taken through the opening is guided to the speed detecting device.

Abstract: Electronic control systems, devices and algorithms are described for improving boat efficiency, safety and convenience, particularly for electric motor powered boats. The overall efficiency of electric boat propulsion is improved by matching the needs of the propeller with the magnetic field requirements of the motor. Efficiency also is improved by limiting slip at different boat speeds. Rapid and fully electronic propeller shut off systems also are described for enhancing public acceptance of electric boats and more convenient cruise control systems are described for improving public acceptance of the boating experience.

Abstract: A method for controlling the electrical system of a marine vessel comprises the steps of measuring a battery potential, comparing the battery potential to a threshold voltage magnitude, and then disconnecting one or more of a plurality of electrical power consuming devices when the voltage potential is less than the threshold voltage magnitude. This is done to avoid the deleterious condition wherein an engine of the marine vessel is operating at idle speed and attempting to charge the battery while a plurality of electrical power consuming devices are operating and drawing sufficient current from the alternator to prevent the proper charging of the battery. In these circumstances, the battery potential can actually be depleted as the battery attempts to provide the additional required electrical current for the loads.

Abstract: The personal watercraft vehicle (PWC) component multiplex communication system, as described herein, is configured to accommodate the exchange of information between PWC components. The system employs an engine electronic control unit (ECU), a multipurpose ECU, and a cluster ECU. Management and monitoring data collected from the various PWC components are transmitted to the corresponding ECUs, which process and multiplex the data along with control messages into an aggregate serial data stream and supplies the aggregate data stream to a system bus. System bus interconnects each of the ECUs and accommodates the bi-directional transfer of the aggregate multiplexed data stream to the ECUs and may be configured as a 2-wire interconnection. Accordingly, the ECUs receive and de-multiplex the aggregate data stream containing the data and control messages generated by other ECUs.

Abstract: In a small boat equipped with a display panel (liquid crystal device) displaying operation information and a change-over switch (set switch) capable of switching from a normal operation in which output of an engine is not limited to a limited operation in which the output of the engine is limited low, the display panel has a display lamp (limit mode display mark) for lighting when switched to the limited operation. Since there is provided a display lamp for lighting when switched to the limited operation for a small boat capable of switching from a normal operation in which output of an engine is not limited to a limited operation in which the output of the engine is limited low, the convenience can be afforded to the operator.

Abstract: A network for a vehicle correlates network addresses with functions. The network can be used to connect control devices and an outboard motor mounted to a watercraft. Each physical node on the network can include one or plurality of functional nodes. The network can be configured to assign network addresses to devices on the network based on the functions performed by the devices, respectively.

Abstract: A watercraft is equipped with an outboard motor and an inboard local area network (LAN) that communicates control signals to the outboard motor. An outboard motor operating device retains the ability to operate the outboard motor even if part of the inboard LAN develops an abnormality. In particular, a control signal that controls the outboard motor and a conditional information signal that indicates a condition of the watercraft are transmitted by independent cables that are mutually separated. Even if the cable for transmitting the conditional information signal or equipment connected to the cable develops an abnormality, transmission of the control signal for controlling the outboard motor is not hindered since the control signal is on the other cable, which is not affected by the abnormality. The conditional information signals are processed to generate and display return-to-port warnings based on the watercraft conditions and other operator issued constraints.

Abstract: A network system using a LAN to provide relative position data for a engine in a plurality of outboard motors attached to a watercraft and using that data to display engine condition information for each engine in the array of engines installed on the watercraft.

Abstract: A tell-tale system is provided for an outboard motor in which the tell-tale fluid conduit is connectable to an external water source, such as a water hose, and is extendable away from the cowl of the outboard motor in order to facilitate its use during a flushing operation. When not being used in the flushing procedure, the connector of the fluid conduit is snapped into position in connection with the cowl to maintain its position when used as a tell-tale port.

Abstract: A marine instrument includes a housing, a processor for processing an input signal comprising vessel navigation information, a substantially water resistant display connected to the processor, the display having at least one control switch extending outwardly from the display, a removable face plate having a window, a front surface, and a back surface, the removable face plate having at least one substantially flexible raised portion along the front surface forming a complementary concavity along the back surface, the face plate positioned on the display so that the concavity matingly receives therein the control switch, and so that the display is visible through the window, and a bezel connected to the housing so as to hold the removable face plate in place.

Abstract: A jet-propulsion watercraft can maintain steering capability even during throttle-close operation as the amount of water ejected from a water jet pump is thereby reduced. Engine speed is increased by a push-pull cable provided between a rotational shaft of a steering handle and a throttle lever. The throttle lever is forced to rotate which opens a throttle valve according to the amount of steering. Alternatively, the engine speed is increased by increasing a fuel of an auxiliary air-fuel mixture supplying system provided independently of a main air-fuel mixture supplying system while a throttle-close operation and a steering handle operation are detected. The auxiliary supplying system is provided in a position of an air supplying passage to the main supplying system and an air-fuel mixture supplying passage of the main supplying system directly or indirectly through a predetermined connecting passage.

Abstract: The present invention comprises a remote marine monitoring and control system that compiles security information and statistics for on-board equipment on unattended boats, uses a wireless transmitter to send this data to a user over a communications network and allows a user to remotely operate the user's boat in response. Boat operational data can be provided to a user on a variety of personal communication devices and/or through a monitoring web site. These devices can also be used by the user to send a user command to remotely control the operation of the boat. The remote marine monitoring system identifies normal operating conditions for on-board equipment and compares these conditions to current operating activity in order to detect unusual activity. Security information can also be compiled and reported relating to intrusion sensors, keyless entry and the boat's physical location.

Abstract: An outboard motor reflector for use on boats being towed. The reflector can be attached to a longitudinal arm that is attached to the boat motor either above or below the propeller hub. The reflector can pivot and be oriented to multiple directions so that the reflector remains visible to drivers behind the towed boat regardless of whether the outboard motor is in a down position or is any raised position. Clamp prongs extend about sides of the motor housing and adjustable straps further lock the reflector to the outboard motor.

Abstract: The present vehicle data system collects, encodes, transmits, decodes, and displays engine and vehicle operation information. In one mode, an engine control unit of an outboard boat motor receives a plurality of engine and vehicle operation parameters from a plurality of sensors. The engine control unit encodes the plurality of parameters in a single signal and transmits the encoded signal to a display unit over a signal line. The display unit decodes the encoded signal to extract the plurality of parameters and displays the extracted parameters to the vehicle operator.

Abstract: An outboard motor position responsive system is disclosed that warns and/or prevents a powerboat operator from engaging the ignition system of an outboard motor when the outboard motor is tilted up beyond a maximum safe tilt position. The system comprises an outboard motor position sensor that is in communication with an ignition switch, wherein the sensor activates an alarm and/or an ignition disabling switch when an operator attempts to engage the ignition system when the outboard motor is tilted up beyond the maximum safe tilt position. An interval-on relay is also provided that limits the amount of time that the alarm and/or the ignition disabling switch are activated. The interval-on relay further prevents against wave-induced alarms with certain types of outboard motor position sensors in accordance with the present invention. A device is also provided that is easily retrofittable with the existing ignition system of a powerboat.

Abstract: A Hall effect rotational position sensor is mounted on a pivotable member of a marine propulsion system and a rotatable portion of the rotational position sensor is attached to a drive structure of the marine propulsion system. Relative movement between the pivotable member, such as a gimbal ring, and the drive structure, such as the outboard drive portion of the marine propulsion system, cause relative movement between the rotatable and stationary portions of the rotational position sensor. As a result, signals can be provided which are representative of the angular position between the drive structure and the pivotable member.

Abstract: A hydraulic actuator is provided for an outboard motor system in which the cylinder and piston of the actuator are disposed within a cylindrical cavity inside a cylindrical portion of a swivel bracket. The piston within the cylinder of the actuator is attached to at least one rod that extends through clearance holes of a clamp bracket and is connectable to a steering arm of an outboard motor. The one or more rods attached to the piston are aligned coaxially with an axis of rotation about which the swivel bracket rotates when the outboard motor is trimmed. As a result, no relative movement occurs between the outboard motor, the rod attached to the piston of the actuator, and the swivel bracket during rotation of the outboard motor about the axis of rotation.

Abstract: A battery gauge for an electric trolling motor is disclosed. The battery gauge includes a battery that is configured to supply power to the trolling motor. The battery gauge also includes a motor speed setting switch that is configured to supply a signal representative of the motor speed setting. The battery gauge also includes an electronic circuit configured to sense at least one battery parameter that is representative of the battery charge. The electronic circuit is also configured to receive an electrical signal that is representative of the speed setting. The electronic circuit further is configured to determine the remaining battery charge time based on the at least one battery parameter and the speed setting.

Abstract: A system for measuring propeller apparent slip and angle of attack includes a main console housing a processor. The system measures vessel speed with a pitot tube, pressure transducer, and the processor; and measures engine speed with an inductive pickup and the processor. The processor is programmed with algorithms for determining apparent slip and angle of attack. When the engine gear ratio, propeller diameter, and propeller pitch are manually provided to the processor, the processor computes apparent slip and angle of attack on a substantially real-time basis. The processor routes information to a display screen in the main console, and also to a data logger for permanent data storage.

Abstract: Efficient human-powered or human-power assisted energy generation and transmission system adapted for use with vehicles. The present invention can be utilized to achieve overall energy transmission efficiency superior to mechanical drives that utilize chains and sprockets or other mechanical drive mechanisms. The present invention can completely eliminate the need for multiple sprockets and the associated shifting mechanisms presently used in most bicycles. By utilizing high efficiency, light weight, direct-drive generators and motors, and an input controller, coupled with an efficient energy storage device, the present invention can reduce the overall weight and complexities of mechanical power transmissions, while, at the same time, offer higher overall efficiencies. In addition, the energy output to the output drive device can be controlled, through profiling and with an output controller, to maintain constant output, independent of instantaneous input.

Abstract: A watercraft having a speed measuring system which provides for accurate and consistent measurement of watercraft speed throughout the operation of the watercraft, including during violent maneuvers and/or sharp turns. The speed measuring system includes a ride plate assembly for a personal watercraft comprising a sensor and a plate. The sensor generally includes a moveable element and a housing supporting at least a portion of the moveable element. The plate includes a longitudinally-extending channel with the channel extending along at least a portion of the length of the plate. The housing is connected to an aft portion of the plate with at least a portion of the rotatable element being positioned in line with the channel.

Abstract: A watercraft engine includes a lubrication system alarm control system which initiates an alarm when lubricant pressure within the lubrication system falls below an acceptable pressure. The alarm system compares lubricant pressure during engine operation with a lower pressure threshold which is determined as a function of engine speed. Thus, partial reductions in lubricant pressure are identified. Additionally, the alarm control system may be configured to emit an alarm if lubricant pressure fluctuates at a rate that is greater than a predetermined pressure fluctuation rate threshold.

Abstract: An outboard motor mounting arrangement wherein the swivel bracket and clamping brackets have interengaging sliding surfaces that take side thrusts and minimize loading on the tilt pin during trim operation. In addition, certain electrical cables and hydraulic conduits are juxtaposed to the steering shaft and mounted so that they pass through the various brackets in a location close to the various pivotal axes to minimize flexure and reduce the necessary length therefor.

Abstract: An alarm device of an outboard motor arranged in operative association with an engine thereof to which a sensor device including a plurality of sensors is mounted and operated by a control power source, comprises a central control device into which an operation condition of the engine is inputted, a sensor trouble judging device connected to the central control device and the sensor device for judging a state of trouble of the sensor device, an alarm control device, a sound alarm device controlled by the alarm control device, and an alarm judging device for judging a type of an alarm, which is connected to the alarm control device so as to operate the alarm control device to operate the sound alarm device in response to an information from the sensor trouble judging device.

Abstract: The present invention is an overheat detection system for an engine having at least one cooling jacket which is drained of coolant when the engine stops running. The detection system includes a sensor for sensing a temperature associated with the cooling jacket. The detection system is arranged to output an overheat signal in the event the temperature sensed by the sensor is above a predetermined temperature except within a predetermined time after the engine has been started.

Abstract: The invention relates to an engine control system for an internal combustion engine for propulsion of an associated watercraft. The engine includes an air intake in communication with a combustion chamber of the engine and an air intake adjustment means for altering the amount of air let into the combustion chamber of the engine. There is also an operation device controlling a water propulsion device of the watercraft. The device is movable between a forward, a neutral or a reverse position. A first control means for controls the air intake adjustment means based upon the position of the movable operating device. A second control means controls the air intake adjustment means independent of the first control means based upon a set of predetermined conditions.

Abstract: A system for measuring propeller apparent slip includes a main console housing a processor. The system measures vessel speed with a pitot tube, pressure transducer, and the processor; and measures engine speed with an inductive pickup and the processor. The processor is pre-programmed with an algorithm for determining apparent slip. When the engine gear ratio and propeller pitch are manually provided to the processor, the processor computes apparent slip on a substantially real-time basis. The processor routes information to a display screen in the main console, and also to a data logger for permanent data storage.