A grounding skeg for a landing craft configured for stem landing onto, and setting off from, a ground surface, the grounding skeg including: an elongate grounding body having a fore end and an aft end; and a removable pulling propeller functionally connected to the fore end of the body; wherein the pulling propeller is able to drive the landing craft ahead and astern; and the grounding body is locatable on the landing craft such that: the grounding body provides contact with the ground surface during stem landing of the landing craft; the fore end of the grounding body faces a bow end of the landing craft; and the aft end of the grounding body faces a stem end of the landing craft.

What is provided is a propeller guard apparatus that may be readily configured to a variety of different boat motors. Described embodiments of the propeller guard apparatus comprise a cylindrical housing configured to circumferentially enclose a propeller from all sides in order to protect humans, pets, and aquatic wildlife from being entangled or cut by the propeller. Described embodiments of the propeller guard apparatus also comprise a protective structure, such as a skid plate comprising of at least two pieces of metal attached from the cylindrical housing to an end of the outer casing to form a folded T-shaped configuration. This type of configuration serves to protect the propeller from damage caused by submerged objects and aquatic wildlife found in shallow water. Also, the folded T-shaped configuration may push vegetation, weeds, manatees, and other aquatic wildlife away from the path of the moving boat and its propeller.

A silicone bond coat composition having a viscosity of less than 1,600 centistokes is applied to substantially all external surfaces of the article and then cured. A liquid silicone elastomer outer coat composition comprising a high viscosity first liquid silicone elastomer formulation and a low viscosity second liquid silicone elastomer formulation is then applied and cured to provide a protected article having a complex shape. Optimal coatings result from a careful balancing of component viscosities. In an embodiment, the first formulation has a viscosity greater than 300,000 centistokes, and the second formulation has a viscosity less than 6,000 centistokes, and the liquid silicone elastomer outer coat composition comprises from about 60 to about 40 percent by weight of the first formulation and from about 40 to about 60 percent by weight of the second liquid silicone elastomer formulation.

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 cutting device for coupling to a water vessel propelling device. The cutting device comprises a base extending between a proximal end and a distal end and is coupled to a shaft of the water vessel propelling device. An upper arm is coupled to the base. A lower arm is coupled to the base. A track extends along the base. A blade slidably engages within the track for displacing between the upper arm and the lower arm. An actuator displaces the blade relative to the track. A cutting edge is on the blade for severing a foreign object that is positioned between the upper arm and the lower arm of the base.

A portable propulsion system for a watercraft may include a shaft, a propeller, an outer casing, and a flexible strap. The shaft may have a prop end section, a drive end section, and a rotational axis extending from the prop end section to the drive end section. The propeller may be connected to the prop end section of the shaft. The drive end section may be configured for removable connection to a driver for rotation of the propeller via rotation of the shaft about the rotational axis to propel the watercraft. The outer casing may be disposed around the shaft. The flexible strap may have first and second end sections connected to the outer casing in respective first and second regions.

An objective of the present invention is to provide an underwater ship attachment that is used to divert air, debris, and pressure fluctuations. More specifically, the present invention discloses an anti-cavitation device (such as a diverter device) for flat-bottom boats. The air diverter has been developed to regain, enhance, and protect the operational function of propulsive and steering equipment among displacement and semi displacement hulls. As with protect items such as bottom mounted depth sounder transducers, intakes for engine or general cooling, sea chests, keel coolers, zincs, and all other underwater mounted items susceptible to air ingestion, air disturbance malfunction or debris impact.

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.

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.

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.