A marine propulsion system for shallow waters, swamps, savannahs and the like includes a rotating propeller shaft supporting a propeller. An anti-cavitation body defines a partial cylinder having a longitudinal axis adjacent to the propeller. The propeller generates a vacuum between the anti-cavitation body and a surface of a water body. First and second wings adjacent to edges of the anti-cavitation body are generally planar and operatively angled towards the bottom of a water body. The first and second wings are adjusted to run below the water body surface and seal the anti-cavitation body to maintain generated vacuum. A first thread is cut in a first helical direction at an end of the rotating propeller shaft adjacent the propeller, and slightly more distal therefrom a second thread is cut in a second helical direction opposed to the first thread helical direction. The second thread drives matter away from the bearing.

A drive device for a vessel includes an electric motor, driving a rotatable drive shaft; an elongate drive device housing, encapsulating the electric motor and the drive shaft; and a propeller, detachably mounted to the rotatable drive shaft. The drive device housing has an upper connection device. The upper connection device is symmetrical about a transverse axis, enabling the drive device housing to be mounted to a structure onboard the vessel in either of two longitudinal directions. The drive device and the hull of the vessel are separated from each other by using an isolation plate with a central isolation sleeve. The electric motor drives the drive shaft via an interconnected gear device encapsulated in the drive device housing or integrated as a part of the drive device housing and are arranged pivotably with respect to the tilt device housing.

A marine propulsion apparatus includes a lower unit, the lower unit includes a center body. The center body includes a leading edge disposed at a first end of the center body and a trailing edge disposed at a second end of the center body, defining a substantially cylindrical portion therebetween. The lower unit includes a modular nose cone member releaseably coupled to the leading edge of the center body, the modular nose cone further including a first curved conical surface and a first mating surface. The lower unit includes a modular tail cone member releaseably coupled to the trailing edge of the center body, the modular tail cone further including a second conical surface and a second mating surface, the second mating surface oriented towards and parallel to the first mating surface. The lower unit includes a skeg affixed to a bottom side of the center body.

A boat propulsor includes a duct, a propeller in the duct and rotatable around a rotation axis extending along an axial direction of the duct, and a rotator to rotate the propeller. An upper portion of the duct includes a plate extending from the duct in the axial direction and including holes. Water streams passing around and along the duct are attenuated as the water streams pass through the holes in the plate.

An outboard motor includes a gear housing configured to rotatably house a propeller shaft that transmits a rotative power output from an engine to a propeller device. The gear housing includes a torpedo shape portion and a strut portion. The torpedo shape portion has a shape tapered toward a front side, and a shape biased upward toward the front side. The strut portion is disposed on an upper side of the torpedo shape portion. An outer peripheral surface of the torpedo shape portion is smoothly coupled to an outer peripheral surface of the strut portion via first to third curved surfaces. The first to third curved surfaces are each a curved surface inclined rearward and downward, a curved surface parallel to a front-rear direction, or a curved surface constituted of a part inclined rearward and downward and a part parallel to the front-rear direction.

An outboard motor includes a gear housing configured to rotatably house a propeller shaft that transmits a rotative power output from an engine to a propeller device. The gear housing includes a torpedo shape portion and a strut portion. The torpedo shape portion has a shape tapered toward a front side, and a shape biased upward toward the front side. The strut portion is disposed on an upper side of the torpedo shape portion. An outer peripheral surface of the torpedo shape portion is smoothly coupled to an outer peripheral surface of the strut portion via first to third curved surfaces. The first to third curved surfaces are each a curved surface inclined rearward and downward, a curved surface parallel to a front-rear direction, or a curved surface constituted of a part inclined rearward and downward and a part parallel to the front-rear direction.

An outboard motor for attachment to a hull of a marine vessel includes a lower case including a propeller shaft to rotate a propeller, and an upper case including a drive shaft to transmit a power to the propeller shaft. The lower case is selected from among different types of lower cases to be attached to the upper case, and the upper case and the lower case are connected by an intermediate structure.

A device including an outboard motor including a jet outlet portion, a stabilizer plate, and a rudder, where the stabilizer plate includes a first end portion and a second end portion, where the first end portion is proximal to the jet outlet portion, where the second end portion is distal to the jet outlet portion, where the rudder extends from the stabilizer plate between the first end portion and the second end portion.

A device including an outboard motor including a jet outlet portion, a stabilizer plate, and a rudder, where the stabilizer plate includes a first end portion and a second end portion, where the first end portion is proximal to the jet outlet portion, where the second end portion is distal to the jet outlet portion, where the rudder extends from the stabilizer plate between the first end portion and the second end portion.

The present device relates to boatbuilding, and more particularly to screw propellers with safety couplings, intended for use in outboard motors and/or marine screw propellers. A screw propeller with a safety coupling comprises a screw propeller body-cum-hub, a drive coupling, a driven coupling, and a dowel pin. The driven coupling is disposed for rotation on a spacer bushing, said spacer bushing being a tail bushing of the driving coupling. The driven coupling is partially or completely disposed in an opening in the screw propeller body-cum-hub and transmits torque to the screw propeller body-cum-hub by means of a longitudinal dowel pin and/or longitudinal grooves and a spline coupling. A common opening for the dowel pin in the driving and/or the driven coupling is configured as a through opening, and/or the blind end of the opening for the dowel pin is connected by a transverse opening to the outside surface.