Abstract: A boat drive having a variable-speed engine connected through a clutch to a variable-pitch propeller has a control having a housing and a guide on the housing defining a central crosswise track having a travel end and a start end, forward and backward travel tracks extending from the travel end, and a forward start track extending from the start end. A lever pivoted on the housing is movable in the tracks of the guide. A pitch controller connected to the propeller includes a position detector operable by the lever when in the travel end and travel tracks for increasing propeller pitch positively on movement of the lever forward from the travel end in the forward travel track and negatively on movement of the lever backward from the travel end in the backward track and for setting the propeller at 0° pitch when the lever is in the travel end.

Abstract: An improved shift mechanism for a marine propulsion transmission is provided. The shift mechanism includes a guide that defines a slot that receives a member of a linkage that connects an operator unit with a shift rod. Movement of the shift mechanism is converted into substantially linear motion and a shift position sensor is located at a substantially right angle to that movement. Information from the sensor is transmitted to a control unit and is employed to prevent abrupt starts. The shift position sensor is located on the side of an engine for ease of assembly and maintenance. Movement of the shift mechanism may also cause pivotal movement of the guide and this pivotal movement may be employed to reduce the engine speed and assist shifting.

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 apparatus for controlling a trolling motor, comprising a foot operable control assembly with a rotatable plate operationally connected to the trolling motor so that the rotational motion of the plate will rotate the trolling motor to steer the boat. In one embodiment, the means to activate the trolling motor speeds are operationally connected to the trolling motor and placed in a circle around the rotatable control plate. In another embodiment the operator can place a chair on the rotatable plate to steer the boat and activate the trolling motor speeds with his foot. In still another embodiment the control assembly has a rotatable shaft with a chair attached to steer the boat and the trolling motor speed control means are operatively connected to the trolling motor and placed remotely from the control assembly so that the speed control means are accessible to the foot of an operator.

Abstract: A marine propulsion engine abnormal condition sensing arrangement, specifically a low oil pressure sensor, that is effective to permit a low cost sensor by using a separate power supply circuit that need not pass through the main watercraft control in order to drive the switch. The warning device that is operated by the switch is provided with a separate power supply so that its characteristics need not determine the current that is supplied to the sensor.

Abstract: An idle speed control system for a marine propulsion system controls the amount of fuel injected into the combustion chamber of an engine cylinder as a function of the error between a selected target speed and an actual speed. The speed can be engine speed measured in revolutions per minute or, alternatively, it can be boat speed measured in nautical miles per hour or kilometers per hour. By comparing target speed to actual speed, the control system selects an appropriate pulse with length for the injection of fuel into the combustion chamber and regulates the speed by increasing or decreasing the pulse width.

Abstract: A marine propulsion control that permits the use of transmission braking for a watercraft without the likelihood of engine stalling by increasing engine speed during this condition. Nevertheless normal idle speeds can be maintained when running in neutral. This is accomplished with a single lever control.

Abstract: An outboard motor throttle and transmission control that employs a bowden wire mechanism for transmitting control signals from the tiller handle to the engine throttle and transmission control. The control handle is pivotally mounted on the front end of a tiller arm and the wire actuators exit the control handle and enter the protective cowling on opposite sides of a longitudinal center plane or on opposite sides of the protective cowling so as to increase the length of the wire actuators in this area so as to facilitate their bending without kinking.

Abstract: The present invention is an ignition control system for an engine having an ignition system. The ignition control system is arranged to determine if a speed of the engine is decreasing at greater than a predetermined rate, and if so, to initiate an ignition timing compensation mode in which target engine speeds during the time of deceleration are set. These target engine speeds are compared to the actual engine speed and a firing timing of the ignition is advanced if the actual engine speed is less than the target speed and the firing timing of the ignition system is delayed if the actual engine speed exceeds the target speed.

Abstract: A control apparatus for controlling an engine mounted on a watercraft and driving it so as to finely and stably control a low speed of the watercraft. The control apparatus is adapted to compute a target engine speed on the basis of a correction value for the engine speed which is determined by a correction signal generated by a correction signal generator which is manually operable. The control apparatus controls the opening degree of the secondary air valve in accordance with a desired opening computed on the basis of the computed target engine speed.

Abstract: A personal watercraft catalytic exhaust system wherein an over-temperature sensor is provided that is effective to shut down the engine in the event the catalyst reaches a dangerous temperature. The engine, once shutdown, cannot be restarted until the temperature falls below a predetermined temperature which may be lower than the overheat temperature. In the process of stopping the engine, it is slowed down first so as to give the rider additional warning that the shutdown procedure will be initiated.

Abstract: A slow speed adjustment mechanism is provided that allows an internal combustion engine to be manually adjusted to operate at a slow speed which is slightly faster than the idle speed of the engine. A tubular member is provided with an outer threaded surface and an inner threaded aperture and is rigidly attached to a support plate mounted on the engine. An adjustment head is provided with threads that mate with the threads of the inner threaded aperture of the tubular member. Rotation of the adjustment head moves it axially relatively to an axial end of the tubular member. A flexible shaft can be attached to the adjustment head to allow manual rotation of the adjustment head, whereby the idle speed of the engine can be modified for purposes of trolling or other uses which require a slow operation of the engine at a speed which is slightly greater than its idle speed.

Abstract: A grip 6b is projectingly provided on one side of an upper end of a control lever 4.sub.1, 4.sub.2 of a controller for a boat propelling device, and a switch accommodating portion 7b is projectingly provided on the other side. Control switches 14 and 15 are mounted in the switch accommodating portion 7b. The switch accommodating portion 7b is formed, on its front surface on the side of an operator, with an operating face 23 which is inclined, so that it comes closer to a center plane 21 extending laterally of the control lever 4.sub.1, 4.sub.2 at a laterally outer location. The control switches 14 and 15 have operating buttons 14a and 15a mounted to face the operating face 23. Thus, when the operator grasps the grip portion of the control lever, the thumb of his or her hand is naturally opposed to the operating buttons of the control switches and hence, the operator can extremely easily operate the operating buttons.

Abstract: An apparatus for controlling a trolling motor, comprising a rotatable, foot-operated bearing assembly operationally connected to the trolling motor so that rotational motion of the bearing assembly is transferred to produce rotation of the trolling motor. The apparatus is configured so that, regardless of whether the trolling motor is mounted to the front or the back of the boat, the boat will move in the direction of rotation of the bearing assembly. In one embodiment of the invention, the bearing assembly may support a swivel chair whereby rotation of the chair results in rotation of the trolling motor.

Abstract: A watercraft includes an improved display arrangement located in a steering operator for steering of the watercraft. The steering operator has at least one hand grip. The display arrangement includes a visual display and a display controller connected to the visual display so as to control the display of watercraft operational information on the visual display. The display controller establishes at least two display modes for the visual display to change the type of operational information displayed. A selector is supported by the steering operator near the grip for easy use by the watercraft operator in changing the display modes of the visual display with the display controller.

Abstract: An engine control is provided for controlling an engine powering a planing-type watercraft. The engine control activates a fuel increasing system for providing an additional amount of fuel to said engine over a first amount of fuel during a period of acceleration of said watercraft to its planing speed. In addition, the engine control preferably adjusts the position of an exhaust timing valve to delay the passage of exhaust from the combustion chamber(s) of the engine during that time the additional fuel amount is being provided to the engine in order to prevent overheating and fouling of an exhaust catalyst.

Abstract: In accordance with the present invention there is provided an outboard motor for use in powering a watercraft of the type having an operator station positioned along a starboard side of the watercraft. The motor has a water propulsion device powered by an engine having an exhaust system generally positioned along a right side thereof. A cooling system is provided for cooling the engine and the exhaust system. Preferably, the motor includes a cooling water tell-tale acting as a visual identifier to the operator of the craft that the cooling system for the engine is operating. The tell-tale is created by diverting coolant from a portion of the cooling system for cooling the exhaust system to a pilot port in the side of the cowling corresponding to the starboard side of the watercraft. In addition, the motor preferably includes a throttle control and shift control which extend along the right side of the engine through the cowling to the operator station in the watercraft.

Abstract: An automatic throttle adjustor system for a power boat which is operable to return a carburetor throttle valve to an idle setting from a user-selected setting when a sensor mounted on a bottom of the boat is about to leave the water, and which is operable to return the throttle valve to the user selected setting from the idle setting when the sensor is again submerged in the water. The system includes the sensor, a controller, an actuator, and a throttle linkage. The sensor supplies signals to the controller indicative of whether the sensor is submerged or airborne. The controller uses the signals supplied by the sensor to switch the actuator between a normal, activated state, in which the throttle valve is at the user-selected setting, to a deactivated state, in which the throttle is moved to the idle setting. The throttle linkage includes an element which is in a first position when the actuator is in the activated state and which moves to a second position when the actuator is deactivated.

Abstract: A control handle for the tiller of an outboard motor that embodies a twist-grip throttle control, a pivotally supported transmission control and a trim switch, all juxtaposed to each other but oriented in such a way so that actuation of one will not affect accidental actuation of any other control. The trim control is disposed in a projection on the lower side of the outer housing of the control handle and is disposed inwardly from the sides thereof and is protected by a flange.

Abstract: An outboard drive system that includes a drive assembly and a drive system control assembly. The drive assembly includes a base assembly; a fan propulsion assembly including a internal combustion drive motor, a propeller, and a coupling shaft; a safety cage; a dual rudder assembly; a kill switch wire in electrical connection with the drive motor; a throttle positioning cable assembly; and a rudder positioning cable assembly; the drive system control assembly including a housing structure; a mounting plate; a rudder positioning cable control stick; a manual kill switch button; and a spring loaded throttle cable control trigger.

Abstract: Ski rider controls to control throttle and steering of a ski rider. The ski rider controls are flexibly and adjustably secured to the ski rider. The operator may grip the ski rider controls in his two hands, squeezing with one hand to turn the ski rider in one direction and squeezing with the other hand to turn the ski rider in the opposite direction. A thumb-operative thumb throttle is provided on the ski rider controls in order to control acceleration of the ski rider.

Abstract: An improved propulsion unit control system for marine units having at least two propulsion systems. A single lever control controls the speed of both propulsion systems and if a difference in speed occurs, the speed of the faster propulsion unit is reduced. In addition, each propulsion unit includes a respective abnormal condition sensor which outputs a signal to a common control system. This common control system reduces the speed of both propulsion units when an abnormal condition is sensed in either unit.

Abstract: A speed controller for vehicle comprises speed sensors which output to a controller which in turn outputs to a servo motor. The servo is connected to the inner cable of a co-axial cable, the outer sheath of which is lodged between a buttress and the engine throttle. The distance between the buttress and the engine throttle lever is, at least when the throttle is closed, shorter than the length of the outer sheath such that the outer sheath obtains a curved configuration. The inner cable extends beyond the engine throttle lever to a support. Accordingly, when the controller operates the servo to draw in the inner cable, the outer sheath is urged to straighten and, thereby, push against the engine throttle lever to open it. Conversely, when the inner cable is paid out, the outer sheath is relaxed to allow the engine throttle lever to close.

Abstract: A control switch assembly for utilization with marine propulsion units to be mounted in, for example, the single lever housing of the transmission and throttle control. The switch assembly includes a sealed outer housing providing at least two cavities for containing switches and a hard wire interconnection to an external terminal for connection to a wire harness.

Abstract: A method and apparatus for controlling the speed of a ship optimizing the configuration of its drive system, e.g., including its engine, geartrain, brake, clutch and screw.

Abstract: An engine rotational number controller includes an engine rotational number detector 5 for detecting the number of rotation of an engine, a throttle opening detector 7 for detecting a throttle opening of the engine, an ignition device 11, a stepping motor 15, an injector 16, and a control circuit 4 for delaying an ignition timing of the ignition device 11 when the number of rotation of the engine becomes higher than a predetermined upper limit in the case where the throttle number is constant and for opening a sub-throttle valve 14 of a throttle valve 12 by means of the stepping motor 15 to increase an amount of intake air and to increase an amount of injected fuel in the injector 16 when the number of rotation of the engine becomes lower than a predetermined lower limit in the case where the throttle opening is constant.

Abstract: A jet propelled watercraft having a pair of jet propulsion units and a pair of powering internal combustion engines with a handlebar assembly for effecting steering of the watercraft. First and second throttle controls are carried by the handlebar assembly for controlling the speed of the engine so as to permit the operator to accelerate one engine upon turning, without taking his hands from the steering control to effect a sharper turn.

Abstract: An ignition control for an internal combustion engine accurately determines current engine operational status (acceleration or deceleration) and controls optimally ignition timing. The exemplary system includes a microcomputer, drive circuits for driving ignition coils from outputs of the microcomputer, and a waveform shaping circuit for shaping signal pulses from a crank angle sensor before into the microcomputer. The microcomputer calculates changes in engine speed from wave-shaped signal pulses and determines acceleration rate relative to the maximum attainable acceleration from the speed changes. The microcomputer controls the ignition timing based on the determined acceleration rate. Thus, a complicated throttle link or throttle opening sensor is not necessitated to perform acceleration responsive engine control.

Abstract: A steering and speed control mechanism is disclosed for a hand-controlled trolling motor. The mechanism includes a yoke assembly having a first section attached to the trolling motor and a second section hingedly attached to the first section. There is a control arm extension, which includes an axially rotatable shaft that carries a handle. A tubular receptacle operably engages the control arm of the trolling motor. A universal joint pivotably interconnects the receptacle and the shaft. A tubular sleeve interconnects the shaft to the second section of the yoke assembly such that the shaft is pivotable and axially rotatable relative to the second section of the yoke assembly. The trolling motor control arm is operated through the control arm extension to control steering and speed of the trolling motor.

Abstract: A throttle and transmission control assembly adapted to be mounted on the tiller of an outboard motor for controlling its transmission and throttle. Both the transmission and throttle controls employ devices that convert rotary into reciprocating motion and which amplify the reciprocating motion so as to permit a compact assembly. The movable components are all mounted on a single piece of the assembly so as to minimize manufacturing variations and to simplify the overall construction. In addition, an interlock is provided that controls the maximum speed at which the engine can be operated when in neutral and for blocking shifting into neutral from forward or reverse when operating at a greater than a predetermined speed but for permitting forced movement into neutral under some engine speeds and, at the same time, reducing the engine speed to the maximum permitted at neutral upon such shifting.

Abstract: A trolling valve safety device that locks or limits actuation of a boat engine throttle from its idle position during use of a trolling valve, and vice versa, preferably includes a rotating control plate having mounts for throttle cables so that throttle actuation requires plate rotation. This rotation can be limited by a cam slider which slides under force of trolling valve control cables and provides a cam member that inserts in control slots of the control plate. The cam member is positioned in a locking radial slot when the trolling valve is engaged and thereby locks or limits engine throttling. The cam member is positioned in a releasing arcuate position when the trolling valve is disengaged and thereby permits rotation of the plate and associated engine throttling. A stop pin can also extend from the plate to selectively permit or limit rotation of the plate by alignment or disalignment with a groove in the cam slider and can be adjustable to permit slight throttling during trolling valve use.

Abstract: A control system for a fishing boat trolling motor comprises a pair of cables running from a first pulley on the motor shaft to a second pulley on a bearing assembly that supports a swivel chair so that rotation of the chair produces rotation of the trolling motor. The cables are arranged so that, regardless of whether the trolling motor is mounted to the front or the back of the boat, the boat will be moved in the direction the chair is rotated and two degrees of motor rotation are produced for each degree of chair rotation. The on/off or forward/off/reverse switch for the motor is also attached to a control panel on the chair and rotatable therewith. The switch is preferably positioned to be operated by movement of the user's leg and biased in the off position. Preferably, a motor polarity reversing switch and speed control are also operated from the control panel with the on/off switch.

Abstract: A remote control operator for a marine propulsion transmission and throttle control that is operated by a single control lever. The single control lever's position is sensed and a single servomotor is operated which operates both the transmission control and throttle control through a cam and follower mechanism. A warmup control is also incorporated that permits partial opening of the throttle for warmup operation.

Abstract: A warning system embodied in a remote control system which includes a warning circuit and which alerts the individual operating the system if the position of a controlled member of the system does not correspond with the position of the remote operator of the system within a preset period of time after the operator is moved.

Abstract: The invention concerns a control system for operating a drive assembly of a ship. The system consists of an engine (1), a transmission (3) and an adjustable clutch (4) for forward and reverse motions. A control station (15), a control lever (27) and a control electronics (15) are provided for adjusting the direction of motion and the speed of the ship. In order to influence the reaction of the ship when changing direction, several reversing aids are provided according to the invention. The pilot can use the reversing aids by actuating a selection key (24) located on the control station.

Abstract: The present invention is an auxiliary steering handle apparatus adaptable to most boat mounted trolling motors. The apparatus is comprised of two main components, the pivotal telescopic handle or lever and a split gear housing or case. The pivotal handle or lever is both rotatable and telescopically extendable. Bevel and pinion gears are provided, with the bevel gear split into two halves for clamp mounting to the rotatable steering column of an existing electric trolling motor. Manual rotation of the handle facilitates rotation of the pinion gear and bevel gear, thus axial rotation of the motor is achieved in a full 360 continuous or by-directional rotation. Electrical commutation located within the case and lever, provides sliding electrical contact between a battery and the electric trolling motor.

Abstract: In a helm, throttle and directional control system for small craft, a safety device arranged to operate between an actuating member and an actuated member has such members coupled rotatively together by means of mechanical one-way coupling devices wherein a resilient force holds the actuated member constantly biassed to a locked position, and wherein the locking action is released by moving the actuating member against the resilient force, thereby motion can be transferred to the actuated member from the actuating member.

Abstract: Several embodiments of steering controls for connection to larger displacement outboard motors that are normally remotely controlled. Each tiller assembly includes at least a throttle control that is connected to the throttle control cable of the outboard motor and a transmission control that is connected to the transmission control cable of the outboard motor. In addition, embodiments of interlocks are depicted that are supported in the tiller assembly and which control the maximum speed of the engine when the transmission is in neutral or reverse and which also prevents shifting into these speeds when the outboard motor is being operated at speeds higher than the those maximum permitted in their respective transmission speeds.

Abstract: A method and apparatus for controlling a propulsion engine output in a vessel, based on the net axial force on a propeller shaft in the vessel. The apparatus includes a regulating loop with a computer which continuously controls the delivery of fuel to the vessel's engine, and optionally controls the attack angle of the vessel's propeller blades. Control of the fuel delivery is performed in accordance with predetermined control algorithms, and optionally, by operator-set parameter values and maneuvering operations. The apparatus further includes at least one force sensor mounted to a bearing which supports the vessel's propeller shaft. The force sensor, which is preferably mounted to a thrust bearing, detects a net axial force on the propeller shaft. The net axial force detected is then used as a parameter in the control algorithms and therefore as a factor in controlling the delivery of fuel.

Abstract: A jet motor powered water vehicle is disclosed which is designed for single person use. The jet powered boat includes a deck having a flat surface portion enabling a person to lie prone thereon while manually controlling the motor and steering the boat by utilizing of a joystick mounted on the deck. The hull of the boat has a generally wide and shallow V-shaped configuration at a bore, lower portion thereof. The hull also has a flat bottom surface at mid and aft lower portions thereof which blend with the V-shape. The hull also includes a rear portion which is curved and upwardly slanted at a lower portion thereof. The boat also includes a transom which is generally rounded for improved aquadynamics, and a shroud generally enclosing the nozzle for the motor impeller is contoured and shaped to generally conform to the V-point of the hull in order to enhance aquadynamics of the hull.

Abstract: A remote control system for transmitting control movement to a throttle and transmission actuator of an outboard drive unit having an engine. The system preferably includes two remote control units each having an operator that is movable between a plurality of positions and is mechanically connected to an actuator unit. A transmitter wire mechanically connects the actuator unit to the throttle actuator for actuating it to open or close the throttle valve(s) of the engine in response to movement of a selected one of the operators. A position detector detects the position of the selected operator and another position detector detects the position of the transmission actuator and each detector outputs a signal to a controlling unit indicative of its detection result. An electric motor driven actuator is electrically connected to the controlling unit and is operated to effect movement of the transmission actuator when the signals outputted by the position detectors are not in agreement.

Abstract: A tiller handle is provided for use with one or more push-pull cables innerconnected to the shift and the throttle mechanisms of an outboard marine engine to control the shift and the throttle operations of the engine. The tiller handle includes a rotatable cam member with one or more cam tracks located on its outer surface. Each push-pull cable is maintained within a distinct cam track such that rotating the rotatable cam member actuates the push-pull cables thereby controlling the operation of the shift and the throttle mechanisms of the engine.

Abstract: In a helm, throttle and directional control system for small craft, a safety device arranged to operate between an actuating member and an actuated member has such members coupled rotatively together by means of mechanical one-way coupling means wherein a resilient force holds the actuated member constantly biased to a locked position, and wherein the locking action is released by moving the actuating member against the resilient force, whereby motion can be transferred to the actuated member from the actuating member.

Abstract: A marine propulsion device comprising a propulsion unit which is adapted to be mounted on a boat and which includes a propeller shaft and an internal combustion engine drivingly connected to the propeller shaft, the engine including engine block structure having a combustion chamber and defining an air intake passage communicable with the combustion chamber, a throttle plate movably supported by the engine block structure and located in the air intake passage, structure for moving the throttle plate in response to movement of an operator control member, and structure supported by the engine block structure for providing a signal indicating the position of the control member independent of the position of the throttle plate.

Abstract: The present invention provides an improved throttle opening control device for a marine propulsion arrangement. The invention allows an operator of a marine propulsion unit to shift from a forward or reverse operating state into neutral, in order to start or restart an engine, or to effect an urgent transmission shift change during operation, without having to execute an independent step of separately reducing the throttle opening beforehand. According to the present invention, the angle of throttle opening is automatically controlled by an interconnection to the transmission shifting system of the propulsion arrangement.

Abstract: A readily mountable and removable carburetor-adjusting control harness accessory for use with a jet-propelled personal watercraft having a deck with a top engine compartment opening and a hood in sealed engagement with the deck at the periphery of the compartment opening to prevent entry of water into the Compartment, the harness having at least one coaxial structure comprising an outer casing and an inner flexible rotatable but non-twistable shaft, one end of the casing of each coaxial structure being in sealed relationship between the hood and the deck with that one end extending to the outside of the compartment when the compartment is closed by the hood, the inner shaft of each said structure extending throughout the length of the respective casing and beyond the ends of the casing, the outer manually accessible end of each shaft having a manually rotatable knob thereon for remote adjustment of a carburetor adjusting member on the other end of the shaft, a bracket structure for anchoring the carburetor en

Abstract: A combination throttle/shift control system, configured for providing the full control of throttle and shift functions on a single lever, taught in the exemplary embodiment in conjunction with a marine propulsion system. The preferred embodiment of the present invention allows the full control of propulsion systems throttle and control functions in a single lever, as opposed to most traditional designs, which require the utilization of separate control levers and cables. This is accomplished via the utilization of a relay triggered actuator arrangement wherein there is provided a magnetic switch system for monitoring the positioning of the actuator travel rod relative a switched relay system. The present invention simplifies both the use and mechanical complexity of throttle and shift control systems, resulting in an appreciable increase in the ease of use, while reducing overall expense and maintenance requirements.

Abstract: This invention relates in general to an electro-mechanical engine control system configured in such a manner as to provide redundant engine controls for marine engines. Microprocessor based, electronic controlled mechanical servos and an electro-mechanical transferring apparatus, facilitates the integration of the electronic control system with mechanical engine controls as they are known to the marine industry of today. This combination of electronic engine controls, integrated with clutch driven servos and mechanical transferring mechanism provides the operator of any marine craft the ease of operation of electronic controls with the security of mechanical backup operation in case of power or system failure.

Abstract: Method and apparatus for converting a watercraft having on-board engine and guidance controls into a drone remotely controlled through towing apparatus by the skier riding on skis behind it. A control unit is secured to the watercraft. The control unit engages the on-board engine and guidance controls of the watercraft. The engine and guidance controls are operated by the control unit through a remotely located tow handle. The tow handle is physically and electronically connected to the control unit.

Abstract: A computer-based system controls (i) speed, (ii) speed and acceleration and/or (iii) trim. Trim control is responsive to sensed inclination. Inclination/acceleration is sensed by an inclinometer/accelerometer having an electrically conductive fluid that flows within a conduit. The fluid assumes different positions in its flow path under differing gravitational and acceleration forces. A multiplicity of pins, positionally arrayed along the fluid flow path within the conduit, electrically sense the presence, or absence, of the fluid at a corresponding position within its flow path. The same computer-based system otherwise used for speed, acceleration and/or trim control also serves as a safety system interactive with a human operator for the sequencing and control of activities during the launch, use, and recovery of the power boat.