An intentional fluid manipulation apparatus (IFMA) assembly with a first thrust apparatus that imparts a first induced velocity to a local free stream flow during a nominal operation requirement. The first thrust apparatus creates a streamtube. A second thrust apparatus is located in a downstream portion of the streamtube. The second thrust apparatus imparts a second induced velocity to the local free stream flow. The second induced velocity at the location of the second thrust apparatus has a component in a direction opposite to the direction of the first induced velocity at the location of the second thrust apparatus.

The invention relates to an arrangement for multi screw vessels, in particular twin screw vessels, with external propeller shafts, as well as to a method for producing such an arrangement. The arrangement according to the invention is in particular suitable for a drive system of an above-mentioned multi screw vessel and to improve the energy efficiency thereof.

The invention relates to an arrangement for multi screw vessels, in particular twin screw vessels, with external propeller shafts, as well as to a method for producing such an arrangement. The arrangement according to the invention is in particular suitable for a drive system of an above-mentioned multi screw vessel and to improve the energy efficiency thereof.

A linking drive system comprises a first drive shaft of the first drivetrain connected between a first prime mover and a first propulsor. The linking drive system comprises a second drive shaft of the second drivetrain connected between a second prime mover and a second propulsor. The linking drive system further comprises a linking drive clutch, which comprises at least a first clutch part and a second clutch part. The first clutch part and the second clutch part are engageable with each other and can transmit rotation therebetween. At least one flexible drive link is coupled between the linking drive clutch and the first and/or second drive shafts. Rotation from one of the first and second drive shafts is transferred to the other of the first and second drive shafts when the linking drive clutch is engaged thereby linking the first and second drivetrains.

A linking drive system comprises a first drive shaft of the first drivetrain connected between a first prime mover and a first propulsor. The linking drive system comprises a second drive shaft of the second drivetrain connected between a second prime mover and a second propulsor. The linking drive system further comprises a linking drive clutch, which comprises at least a first clutch part and a second clutch part. The first clutch part and the second clutch part are engageable with each other and can transmit rotation therebetween. At least one flexible drive link is coupled between the linking drive clutch and the first and/or second drive shafts. Rotation from one of the first and second drive shafts is transferred to the other of the first and second drive shafts when the linking drive clutch is engaged thereby linking the first and second drivetrains.

A controller for a watercraft controls first and second marine propulsion devices to start moving the watercraft by setting a first default angle, a second default angle, and a default thrust ratio as a first target rudder angle, a second target rudder angle, and a target thrust ratio respectively when a desired motion of the watercraft is straight sideways movement. The controller determines at least one of a first correcting angle, a second correcting angle, and a correcting thrust ratio to reduce an error between the straight sideways movement of the watercraft and an actual motion of the watercraft. The controller corrects the first target rudder angle, the second target rudder angle, and the target thrust ratio with the first correcting angle, the second correcting angle, and the correcting thrust ratio, respectively. The controller repeatedly detects the error and repeatedly updates the correcting angles and the correcting thrust ratio.

A controller for a watercraft controls first and second marine propulsion devices to start moving the watercraft by setting a first default angle, a second default angle, and a default thrust ratio as a first target rudder angle, a second target rudder angle, and a target thrust ratio respectively when a desired motion of the watercraft is straight sideways movement. The controller determines at least one of a first correcting angle, a second correcting angle, and a correcting thrust ratio to reduce an error between the straight sideways movement of the watercraft and an actual motion of the watercraft. The controller corrects the first target rudder angle, the second target rudder angle, and the target thrust ratio with the first correcting angle, the second correcting angle, and the correcting thrust ratio, respectively. The controller repeatedly detects the error and repeatedly updates the correcting angles and the correcting thrust ratio.

A multihull stepped planing boat with multiple independent elastic planing surfaces includes: a main hull, X front planing sub-hulls arranged side by side under a front portion of the main hull, and Y rear planing sub-hull arranged side by side under a rear portion of the main hull; wherein X and Y are positive integers, and 3≤X+Y≤8; the X front planing sub-hulls are equally spaced, and the Y rear planing sub-hulls are also equally spaced; there is a gap between the X front planing sub-hulls and the Y rear planing sub-hulls. The planing surface of the main hull is formed by a plurality of independent and spaced sub-planing surfaces. There is a certain elastic buffer space between each sub-planing surface and the main hull, and the shock absorption structures can absorb most of the shocks, thereby reducing the impact of water surface waves during high-speed navigation.

Implementations of a boat propulsion and guidance system are provided. In some implementations, the boat propulsion and guidance system comprises one or more conduits and propulsion devices. In some implementations, the boat propulsion and guidance system may further comprise one or more valve devices. In some implementations, the boat propulsion and guidance system may further comprise a controller. In some implementations, a method of using the boat propulsion and guidance system comprises installing the boat propulsion and guidance system to a boat and operating the boat propulsion and guidance system to move (e.g., steer, maneuver, and/or otherwise propel) the boat in one or more directions. In some implementations, the method may further comprise operating the boat propulsion and guidance system to dynamically anchor the boat to remain in a desired position in the water.

Implementations of a boat propulsion and guidance system are provided. In some implementations, the boat propulsion and guidance system comprises one or more conduits and propulsion devices. In some implementations, the boat propulsion and guidance system may further comprise one or more valve devices. In some implementations, the boat propulsion and guidance system may further comprise a controller. In some implementations, a method of using the boat propulsion and guidance system comprises installing the boat propulsion and guidance system to a boat and operating the boat propulsion and guidance system to move (e.g., steer, maneuver, and/or otherwise propel) the boat in one or more directions. In some implementations, the method may further comprise operating the boat propulsion and guidance system to dynamically anchor the boat to remain in a desired position in the water.