A watercraft includes a hull, a wave detector to detect wave conditions on a water surface, a trim adjuster to adjust a trim angle of the watercraft, and a controller. The controller is configured or programmed to determine, based on a detection value of the wave detector, whether or not the water surface is smooth and, if it is determined that the water surface is not smooth, control the trim adjuster to increase the trim angle.

A watercraft includes a hull, an engine to generate power to propel the hull, an engine speed sensor to detect the rotation speed of the engine, and an ON/OFF sensor to be turned on and off according to a vertical acceleration of the hull. The watercraft further includes a controller configured or programmed to determine, based on at least one of a detection value of the ON/OFF sensor and a detection value of the engine speed sensor, whether or not a water surface is smooth.

The present disclosure relates to a vessel propelling mechanism. In one aspect, a vessel propelling system includes a motor and a waterjet system. The waterjet system is coupled to the motor and includes a stator with a plurality of blades. A first blade of the plurality of blades has a shape that is different than remaining blades of the plurality of blades, the shape of the first blade allowing a driving mechanism of the motor to be coupled to a shaft within the waterjet system.

An accelerating ducted propeller system for propelling boats offers enhanced performance, having the front end of the nozzle disposed at a radial distance (H) between 0.045D and 0.082D from the inner radius of the nozzle, where D is the inner diameter of the nozzle. The front end of the chord of the axial profile of the nozzle has a larger radius than the rear end of the chord with respect to the axis of rotation of the propeller. The inner surface of the nozzle at the axial distance (J) of 0.025D from the rear end of the output edge of the nozzle is at a radial distance from the inner radius of the nozzle of more than 0.0040D and less than 0.0300D. The radial difference between the inner radius of the nozzle and the outer radius of the profile of the nozzle is less than 0.092D.

A water-jet propulsion unit includes a body, an impeller for moving water, the impeller disposed in an impeller tunnel, an impeller shaft for driving the impeller, a first bearing housing to support the impeller shaft on the body, and a jet nozzle for forming a water jet. The body comprises a shaft opening for the impeller, a flow duct having a first contact surface, an inlet opening, and an outlet opening, the planes of which are at an angle α relative to each other. The impeller tunnel has a first end comprising a planar second contact surface and a second end comprising a planar third contact surface to seal the impeller tunnel between the body and the jet nozzle. The second and third planar contact surfaces of the impeller tunnel are arranged at an angle relative to each other. The impeller shaft is adapted for alternative types of installation by turning the impeller tunnel through 180° about the rotational axis of the impeller shaft. Support equipment supports the impeller shaft on the body in the alternative positions.

A jet propulsion watercraft includes a watercraft body, a drive source in the watercraft body, a jet pump to suck and eject water with a drive force from the drive source to generate a propulsive force, a vibration sensor, and a controller. The vibration sensor is located in the jet pump to detect vibration of the jet pump. The controller is configured or programmed to determine whether or not a detection result from the vibration sensor meets a predetermined condition. The controller is configured or programmed to, when it is determined that the detection result from the vibration sensor meets the predetermined condition, inform a user of user-oriented information.

A surfboard with a deck (17), an electric drive for the surfboard (2), wherein one end of a rope (7) is fastened to the bow (4) of the surfboard (2) and another end of the rope (7) has a handle (8), wherein the drive is connected to a controller (21), which comprises a receiver (25) of a wireless remote control, and the handle (8) has an accelerator lever (23) which is connected to a transmitter (24) of the wireless remote control in a data conducting manner, and the transmitter (24) is arranged in the handle (8), and by actuation of the accelerator lever (23) control signals can be generated, which can be transmitted by the transmitter (24) as wireless signals and can be received by the receiver (25) and can be converted by the controller (21) into control values for the drive.

A novel watercraft propulsion device is disclosed that includes multiple propulsive elements improving power and efficiency over prior designs. A self-adjusting variable pitch propeller is combined with a water jet and an exhaust driven turbine to provide optimal thrust and efficiency across the range of engine power, load and watercraft speed. In the preferred embodiment, propulsive elements are axially disposed around a central drive shaft and exhaust port with the combined water jet/exhaust turbine disposed closest to drive shaft and the variable pitch propeller attached to the exterior of the water jet housing. A rotating duct is fixed to the propeller blades and rotates with the blades to reduce cavitation. Combined apparatus provides increased performance and efficiency over all watercraft speeds/load as well as additional safety due to the ducted propeller.

Disclosed is a boat with at least one combustion engine positioned on or symmetrical with the vertical median plane of the boat and two engines provided symmetrical with respect to the vertical median plane, each including a propeller in a duct with: a central section on which the propeller is positioned, a rear section leading via a rear opening onto the transom of the hull, a front section with a continuous curved profile, leading via a side opening to the outside wall of the hull, the side opening having a larger cross-section than the cross-section of the rear opening in order for the duct to include at least one converging nozzle, the front section being oriented so that the stream of water exiting from the side opening is directed towards the front and forms an angle of 20° to 60° with respect to the wall of the hull.

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.