According to the present disclosure there is provided an arrangement for influencing liquid flow, the arrangement comprising: a first section selectively configurable to provide a vortex generator surface to induce vortices in the liquid flow. The arrangement further comprises a second section, wherein the first section and second section are movable relative to one another to provide the vortex generator surface.

According to the present disclosure there is provided an arrangement for influencing liquid flow, the arrangement comprising: a first section selectively configurable to provide a vortex generator surface to induce vortices in the liquid flow. The arrangement further comprises a second section, wherein the first section and second section are movable relative to one another to provide the vortex generator surface.

A built-in propulsion system includes an engine, a diversion unit with a diversion base and an exhaust pipe, and a propulsion unit. The diversion base is connected to the engine, having a water inlet, a water outlet, a diversion channel in communication between the water inlet and the water outlet, a shaft hole above the water inlet and an exhaust chamber behind the shaft hole. The exhaust pipe is fixed on the outer periphery surface of the diversion base in communication with the exhaust chamber. The propulsion unit includes a transmission shaft inserted through the shaft hole and connected to the engine, and an impeller located in the diversion channel and connected to the transmission shaft. The exhaust pipe is used to exhaust the exhaust gas of the engine to the outside of the diversion base to avoid the interference of the exhaust gas and the water flow.

Embodiments of the present invention are directed to devices adapted to enhance propulsion (i.e., propulsion enhancing devices) of watercraft such as, for example, personal watercraft and the like. To this end, a propulsion enhancing device in accordance with the disclosures made herein may be attached to or integral with (e.g., formed unitarily with a housing thereof) a propulsion unit of a watercraft. The propulsion unit generates a stream of water that provides for propulsion of the watercraft. A propulsion enhancing device in accordance with the disclosures made herein includes internal structures that enhance velocity and/or volumetric attributes of a stream of water generated by the propulsion unit by transforming non rotational flow at the inlet of the propulsion enhancing device to rotational flow at the outlet of the propulsion enhancing device.

An outboard drive assembly for a work boat is provided. In embodiments, an outboard drive assembly includes a lower outdrive assembly including: a housing extending between a first and end a second end and having a motor housed therein; a propeller mounted to the first end of the housing; first and second fins extending horizontally from opposing side portions of the motor housing; a third fin extending vertically from the housing; respective cutting blades attached to respective end portions of each of the first, second and third fins adjacent the propeller; an upper outdrive assembly including mounting brackets configure to connect the upper drive assembly to a deck of a work boat; and a drive arm assembly pivotally mounted to the lower outdrive assembly at a first end of the drive arm assembly and mounted to the upper outdrive assembly at a second end of the drive arm assembly.

The present invention relates to a hull in particular for a container ship, a bulk carrier and a tanker. The hull includes an elevation of an outer contour of the hull with respect to an upwards directed vertical direction of the hull in the region of a first body plan and a second body plan in relation to a surface section immediately adjoining to the elevation. Therein, the elevation is arranged in a region between a middle and a stern of the hull.

The present invention relates to a hull in particular for a container ship, a bulk carrier and a tanker. The hull includes an elevation of an outer contour of the hull with respect to an upwards directed vertical direction of the hull in the region of a first body plan and a second body plan in relation to a surface section immediately adjoining to the elevation. Therein, the elevation is arranged in a region between a middle and a stern of the hull.

A control apparatus for an outboard motor (4, 5) mounted on a hull (2), comprises a detection unit (46) that detects a variation of rotation of a propeller (25), a protruding portion (60) provided at a rear end portion (25b) of the propeller (25) to rotate integrally with the propeller (25) and extending from the propeller (25) to a rear of the hull (2), and a control unit (30, 40) that determines that an object has contacted the protruding portion (60) when a variation of rotation of the propeller (25) exceeds a predetermined threshold is detected.

A grid (100) is for a tunnel thruster (200). The grid (100) includes a plurality of first radially extending bars (101) arranged at angular intervals from each other, and a plurality of first connecting bars (102). Each of the first connecting bars (102) are connected between adjacent first radially extending bars (101).

A built-in propulsion system includes an engine, a diversion unit with a diversion base and an exhaust pipe, and a propulsion unit. The diversion base is connected to the engine, having a water inlet, a water outlet, a diversion channel in communication between the water inlet and the water outlet, a shaft hole above the water inlet and an exhaust chamber behind the shaft hole. The exhaust pipe is fixed on the outer periphery surface of the diversion base in communication with the exhaust chamber. The propulsion unit includes a transmission shaft inserted through the shaft hole and connected to the engine, and an impeller located in the diversion channel and connected to the transmission shaft. The exhaust pipe is used to exhaust the exhaust gas of the engine to the outside of the diversion base to avoid the interference of the exhaust gas and the water flow.