Abstract: A propeller device for a marine vehicle with a main shaft; a front propeller is provided on the main shaft, the front propeller having a hub and a plurality of blades extending radially outwardly from the hub; a rear propeller being co-axially to and spaced from the front propeller, the rear propeller having a hub and a plurality of blades extending radially outwardly from the hub. A second shaft being communicated with the hub of the front propeller; and at least one support for supporting the rear propeller on the second shaft, the support prevents the second shaft to rotate in the direction of rotation of the main shaft, and being free to rotate thereof in the counter direction of rotation of the main shaft.

Abstract: The present invention relates to an underwater foil (1) for a marine vessel of the type floating on water disposed completely below the waterline and extending in the port-starboard direction. The underwater foil (1) comprises a plurality of foil members (2, 3) connected to each other in order to form the underwater foil (1).

Abstract: A concealable fender assembly comprising a fender; a cover having an external surface form compatible with the lateral surface form of the boat hull in closed position; mechanism for actuating the cover for closing and opening thereof with respect to the boat hull lateral surface; wherein the cover is associated with the fender such that when the cover is in open position, the fender outwardly extends from boat hull lateral surface.

Abstract: The present invention relates to a marine propeller arrangement comprising a propeller communicating with a shaft connected to the motor of a marine vehicle, the propeller having a hub and demountable blades, wherein each blade comprises a hub portion being integral with each blade and having plurality of bores for securing thereof; and the arrangement comprises a sleeve having a shaft receiving bore, wherein each hub portion is supported by the sleeve and secured thereto via a plurality of securing elements.

Abstract: A marine vessel propeller comprising an even number of blades such as 4, 6, 8, which can be mounted or demounted to a hub made of two parts each having the half of the blades. The blades can be rigidly connected to each other by means of connecting members.

Abstract: A self-adjustable pitch marine vessel propeller attached to a shaft is driven by an engine of a marine vessel, and includes a substantially cylindrical hollow hub and a plurality of blades extending radially outwardly from the hub and being capable of rotating around an axis being in a radial direction relative to the hub. The propeller comprises an actuator movable linearly along the axis of the hub and at least one motion transmission means communicating with the actuator and each blade for converting the linear motion of the actuator into the rotational motion of each blade in a radial direction relative to the axis of the hub and a resilient member communicating with the actuator.

Abstract: The present invention relates to a mechanically-adjustable pitch marine vessel propeller attached to a shaft driven by an engine of a marine vessel, comprising a substantially cylindrical hollow hub and a plurality of blades extending radially outwardly from the hub and being capable of rotating around an axis being in a radial direction relative to the hub. The propeller according to the present invention comprises an actuator movable linearly along the axis of the hub and at least one motion transmission means communicating with the actuator and each blade for converting the linear motion of the actuator into the rotational motion of each blade in a radial direction relative to the axis of the hub.

Abstract: The present invention relates to an underwater foil (1) for a marine vessel of the type floating on water disposed completely below the waterline and extending in the port-starboard direction. The underwater foil (1) comprises a plurality of foil members (2, 3) connected to each other in order to form the underwater foil (1).

Abstract: A dual-rudder control mechanism suitable for use in the sailboats (1), comprising an extendable pivot (8) having each end a respective rudder, mechanism (20) for extending the pivot (8) length, and a control mechanism being responsive to tilting angle of the sailboat (1), and activating or deactivating the mechanism (20) for extending the pivot length in response to the threshold tilting angle of the sailboat body.

Abstract: An arrangement for the maneuver control of a twin-engine boat (1) includes an extendible rod (6) connected to the engines (8) from its ends for changing the boat thrust direction of the engines (8) and a mechanism for moving the extendible rod (6) relative to the boat (1) in the longitudinal axis direction thereof.

Abstract: Boat cabin construction, which can be built in significantly short time, is low cost and suitable for decorative modifications.

Abstract: An arrangement for the maneuver control of a twin-engine boat (1) includes an extendible rod (6) connected to the engines (8) from its ends for changing the boat thrust direction of the engines (8) and a mechanism for moving the extendible rod (6) relative to the boat (1) in the longitudinal axis direction thereof.

Abstract: A vessel propeller comprising a cylindrical hub rotatable about a rotation axis and a plurality of blades provided radially around the hub with a certain pitch angle. The propeller is characterized in that the hub comprises a blade connection housing helically formed on the cylindrical surface of the hub for the demountable connection of each blade to the hub; each blade comprises a hub connector to be placed in the respective connection housing; and plurality of external connecting members extending axially along the hub thickness for rigidly connecting the hub and plurality of blades.

Abstract: A marine vessel propeller comprising an even number of blades such as 4, 6, 8, which can be mounted or demounted to a hub made of two parts each having the half of the blades. The blades can be rigidly connected to each other by means of connecting members.

Abstract: A wildcat for a windlass for dropping down or hoisting an anchor for a marine vehicle, the anchor being coupled to an end of a chain (3) having inter-engaged horizontal links (5) and vertical links (6), a hole (4) formed at the center of the wildcat for engaging a shaft for rotating the wildcat (1), a bearing surface (12) being radially remote from the center of the wildcat (1) for transferring chain links (5,6) there over, horizontal link housings (7) and vertical link housings (8) each provided one after another along the bearing surface (12) for housing each respective chain link, the housings (7,8) having forms matching contours of each respective chain link.

Abstract: Boat cabin construction, which can be built in significantly short time, is low cost and suitable for decorative modifications.

Abstract: A propeller having a hub with a shaft hole at the center thereof, and a number of blades provided radially around the hub; a shaft connected at one end to a motor driving the marine vehicle, the shaft being adapted to the shaft hole, and having a threaded portion arranged at least partially in the longitudinal direction thereof; at least one bearing provided on the shaft for bearing the propeller to the shaft, the at least one bearing being rotatable in a single direction; a connection hub associated with the hub of the propeller, the connection hub comprising a threaded portion being screwable to the threaded portion of the shaft in the direction opposite to the rotatable direction of the at least one bearing, and being non-screwable to the threaded portion of the shaft in the rotatable direction of the at least one bearing.

Abstract: A marine vessels comprising at least one foil extending downwards from the keel under the body of the vessel. The marine vessel comprises a foil being fully submerged in the water and the angle of attack of which can easily be changed by a low drive force and which can bear the propellers.

Abstract: A wildcat for a windlass for dropping down or hoisting an anchor for a marine vehicle, the anchor being coupled to an end of a chain (3) having inter-engaged horizontal links (5) and vertical links (6), a hole (4) formed at the center of the wildcat for engaging a shaft for rotating the wildcat (1), a bearing surface (12) being radially remote from the center of the wildcat (1) for transferring chain links (5,6) there over, horizontal link housings (7) and vertical link housings (8) each provided one after another along the bearing surface (12) for housing each respective chain link, the housings (7,8) having forms matching contours of each respective chain link.

Abstract: A dual-rudder control mechanism suitable for use in the sailboats (1), comprising an extendable pivot (8) having each end a respective rudder, mechanism (20) for extending the pivot (8) length, and a control mechanism being responsive to tilting angle of the sailboat (1), and activating or deactivating the mechanism (20) for extending the pivot length in response to the threshold tilting angle of the sailboat body.