A method for controlling a marine vessel having first and second steering nozzles and first and second trim deflectors comprises generating at least a first set of actuator control signals and a second set of actuator control signals. The first set of actuator control signals is coupled to and controls the first and second steering nozzles, and the second set of actuator control signals is coupled to and controls the first and second trim deflectors. The acts of generating and coupling the first set of actuator control signals and the second set of actuator control signals result in inducing any of a net yawing force, a net rolling force, and a net trimming force to the marine vessel without inducing any other substantial forces to the marine vessel by controlling the first and second steering nozzles and the first and second trim deflectors. Also disclosed is a system for controlling a marine vessel.

An anti-fouling arrangement in a marine vessel with a marine propulsion system, the propulsion system comprising at least one driveline housing, a torque transmitting drive shaft extending out of the driveline housing, and at least one propeller mounted on the drive shaft. The at least one propeller is electrically isolated from its drive shaft, wherein each electrically isolated propeller is connected to a positive terminal of a direct current power source, and each metallic component to be protected against fouling is connected to a negative terminal of the direct current power source. A control unit is arranged to regulate the voltage and current output from the direct current power source.

An adjustable surf wake system enhances a wake formed by a watercraft travelling through water. The system may include a flap for deflecting water traveling past the stern of the watercraft, and/or a positioner operably connected to the flap for positioning the flap relative to a longitudinal axis of the watercraft between a neutral position and an outward position. Positioning a port flap in its extended position enhances a starboard surf wake, and positioning the starboard flap in its extended position enhances a port surf wake. A wake modifying system for modifying a wake produced by a watercraft traveling through water may include a rudder pivotally mounted to the watercraft for steering the watercraft, a fin pivotally mounted to the watercraft substantially along a centerline of the watercraft and forward the rudder, wherein the fin pivots about an upright axis to modify the wake produced by the watercraft traveling through the water, an actuator mounted within the watercraft and operably coupled to the fin for pivoting the fin relative to the centerline, and a controller mounted on the watercraft allowing an operator to control the actuator and selectively pivot the fin to a desired angle θd relative to the centerline.

The invention relates to an arrangement for measuring salinity in water, which arrangement is part of an impressed current cathodic protection system having an electrical circuit comprising a source of electrical power (310); at least one first electrode (315) connected to a positive pole of the power source (310); at least one second electrode (317) connected to a negative pole of the power source (310); a voltage sensor (341); a current sensor (342); and a control unit (313). The control unit is arranged to initiate a measurement sequence at predetermined intervals, wherein the control unit is arranged to connect at least one first electrode (315) to the negative pole of the power source (310) to act as a cathode; connect at least one passive electrode (326) to the positive pole of the power source (310) to act as an active anode; register the output voltage; register the current; determine the circuit resistance using the output voltage and the current; and calculate the resistivity of the electrolyte based on the determined circuit resistance and at least one stored electrode property value, which resistivity is inversely proportional to the salinity. The invention further relates to a vessel provided with such a measuring arrangement and a method for its operation.

A ship maneuvering system includes a propulsion unit to steer a ship body, a trim adjuster disposed on the ship body, and a controller. The controller is configured or programmed to correct a change in the traveling state of the ship body due to operation of the trim adjuster.

A control system for posture control tabs of a marine vessel assists operations of a steering control. The posture control tabs are mounted on a stern of a hull to move up or down to control a posture of the hull. Actuators actuate the respective posture control tabs. When a steering instruction is provided through the steering control, a processor determines the posture control tab to be actuated and controls the actuator corresponding to the posture control tab determined to be actuated so as to change the position of the determined posture control tab.

Methods of, and apparatuses for, controlling at least one trim tab of a marine vessel are disclosed.

A pump intake adapter for pumping shallow levels of fluid from a surface to be drained, the pump intake adapter including a connection on the pump intake adapter to convey the fluid away from the pump intake adapter; an intake surface on the pump intake adapter; and a portion of the intake surface of the pump intake adapter that in operation does not contact the surface to be drained, and creates an open conduit between the pump intake adapter and the surface to be drained through which fluid may flow, the open conduit being in fluid communication with the connection on the pump intake adapter. Other systems and methods are provided.

A system for controlling a marine vessel comprises an input device for inputting an operator command, a sensor which senses and signals an engine function variable or a vessel dynamic variable, and a first structural element and a second structural element. The first structural element and the second structural element each control speed or direction of motion of the marine vessel, and the first structural element and the second structural element each affect the marine vessel dynamic variable. There is a controller which receives the operator command and the engine function variable or the vessel dynamic variable. The controller moves the first structural element and the second structural element based on the engine function variable or the vessel dynamic variable, after receiving the single operator command.

A wake control system aft of the driveshaft, propeller, and rudder of a vessel includes a fin base and at least one fin slidingly engaged with the fin base. The fin(s) are vertically oriented and extend down into the water surface. The fins are transversely adjustable along the fin base to redirect a wake generated by the boat. In other embodiments, the control system comprises a starboard fin tab adjacent to a port fin tab, each of the independent fin tabs hingeably attached to the aft section of the hull, at the transom. Each fin tab includes at least one extending fin. Fin tabs are selectively deployable and retractable into and out of the water surface to redirect a wake generated by the vessel from one side to the other. A novel underwater exhaust system redirects exhaust depending on speed of the vessel and complements the wake control system.