A watercraft includes a vessel body, a marine propulsion device and a guide. The marine propulsion device is attached to the vessel body and includes a water stream generator that propels the vessel body. The guide is provided on the vessel body and extends astern of the vessel body and toward a center of the vessel body in a width direction of the vessel body from a position located sideward of the water stream generator. The guide inwardly directs water flowing on one lateral side of the vessel body such that confluent timing of the water flowing on the one lateral side of the vessel body and water flowing on the other lateral side of the vessel body is caused to occur earlier than when the guide is not provided on the vessel body.

A watercraft includes a vessel body, a marine propulsion device and a guide. The marine propulsion device is attached to the vessel body and includes a water stream generator that propels the vessel body. The guide is provided on the vessel body and extends astern of the vessel body and toward a center of the vessel body in a width direction of the vessel body from a position located sideward of the water stream generator. The guide inwardly directs water flowing on one lateral side of the vessel body such that confluent timing of the water flowing on the one lateral side of the vessel body and water flowing on the other lateral side of the vessel body is caused to occur earlier than when the guide is not provided on the vessel body.

One embodiment of the invention comprises a method for controlling a marine vessel having a first steerable propulsor, a corresponding first reversing device, a second steerable propulsor and a corresponding second reversing device. The method comprises receiving a first vessel control signal corresponding to a rotational movement and no translational movement command, generating at least a first actuator control signal and a second actuator control signal in response to the first vessel control signal, coupling the first actuator control signal to and controlling the first steerable propulsor and the second steerable propulsor, and coupling the second actuator control signal to and controlling the first reversing device and to the second reversing device. The method creates rotational forces on the marine vessel with substantially no translational forces on the marine vessel.

One embodiment of the invention comprises a method for controlling a marine vessel having a first steerable propulsor, a corresponding first reversing device, a second steerable propulsor and a corresponding second reversing device. The method comprises receiving a first vessel control signal corresponding to a rotational movement and no translational movement command, generating at least a first actuator control signal and a second actuator control signal in response to the first vessel control signal, coupling the first actuator control signal to and controlling the first steerable propulsor and the second steerable propulsor, and coupling the second actuator control signal to and controlling the first reversing device and to the second reversing device. The method creates rotational forces on the marine vessel with substantially no translational forces on the marine vessel.

A system for controlling a marine vessel having first and second waterjets, corresponding first and second steering nozzles and corresponding first and second reversing buckets. The system comprises a speed control device for providing a first vessel control signal that corresponds to a speed to be provided to the marine vessel, a processor configured to receive the first vessel control signal and that is configured to provide at least one first actuator control signal coupled to the first and second waterjets, and at least one second actuator control signal coupled to the first and second steering nozzles and the first and second reversing buckets. The system any of improves upon turns provided by conventional waterjet propulsion systems, improves upon slowing down or stopping marine vessels as is done by conventional waterjet propulsion systems, and improves upon the controllability of the waterjet propulsed marine vessel at low vessel speeds.

A system for controlling a marine vessel having first and second waterjets, corresponding first and second steering nozzles and corresponding first and second reversing buckets. The system comprises a speed control device for providing a first vessel control signal that corresponds to a speed to be provided to the marine vessel, a processor configured to receive the first vessel control signal and that is configured to provide at least one first actuator control signal coupled to the first and second waterjets, and at least one second actuator control signal coupled to the first and second steering nozzles and the first and second reversing buckets. The system any of improves upon turns provided by conventional waterjet propulsion systems, improves upon slowing down or stopping marine vessels as is done by conventional waterjet propulsion systems, and improves upon the controllability of the waterjet propulsed marine vessel at low vessel speeds.

An integrated thruster and ballast system in accordance with some examples herein may include a conduit disposed within a hull of the boat. The conduit includes a first opening in fluid communication with a body of water, a second opening in selective fluid communication with the body of water, and an outlet disposed within the boat. The integrated thruster and ballast system includes a ballast tank in selective fluid communication with the conduit via the outlet, a thruster disposed within the conduit and configured to move water through the conduit, a first valve disposed in the conduit and configured to selectively divide or establish the fluid communication between the conduit and the ballast tank; and a second valve disposed in the conduit and configured to selectively divide or establish the fluid communication between the second opening and the body of water.

An integrated thruster and ballast system in accordance with some examples herein may include a conduit disposed within a hull of the boat. The conduit includes a first opening in fluid communication with a body of water, a second opening in selective fluid communication with the body of water, and an outlet disposed within the boat. The integrated thruster and ballast system includes a ballast tank in selective fluid communication with the conduit via the outlet, a thruster disposed within the conduit and configured to move water through the conduit, a first valve disposed in the conduit and configured to selectively divide or establish the fluid communication between the conduit and the ballast tank; and a second valve disposed in the conduit and configured to selectively divide or establish the fluid communication between the second opening and the body of water.

An electric underwater jet motor designed for vehicles traveling above or below the sea. The electric underwater jet motor includes a plurality of stators for marine crafts; at least one radial stator, at least one rotor, at least two impeller blades, a magnetic bearing; at least one permanent magnet bar; at least one axial stator, hydrodynamic bearing components, a motor housing and an engine fastener; a hydrodynamic jet motor housing; and a control unit including a microprocessor, a software, magnetic bearing distance sensors, counter and speed measurement sensors, gyroscopic balance sensors to provide comfortable travel by collected data to reduce an effect of sea currents and wave movements which are the consequences of seasickness on the passengers at sea, heat and humidity sensors, pressure measurement sensors, voltage and ampere measurement sensors, a motor drive circuitry, software algorithms, an energy management system, a control panel, batteries and battery charging components.

An electric underwater jet motor designed for vehicles traveling above or below the sea. The electric underwater jet motor includes a plurality of stators for marine crafts; at least one radial stator, at least one rotor, at least two impeller blades, a magnetic bearing; at least one permanent magnet bar; at least one axial stator, hydrodynamic bearing components, a motor housing and an engine fastener; a hydrodynamic jet motor housing; and a control unit including a microprocessor, a software, magnetic bearing distance sensors, counter and speed measurement sensors, gyroscopic balance sensors to provide comfortable travel by collected data to reduce an effect of sea currents and wave movements which are the consequences of seasickness on the passengers at sea, heat and humidity sensors, pressure measurement sensors, voltage and ampere measurement sensors, a motor drive circuitry, software algorithms, an energy management system, a control panel, batteries and battery charging components.