174results about "Hull keels" patented technology

Provided is a system including a fin box that allows surboard fins to be installed, removed or adjusted to the front or rear of the board within the box and a means for installing the box on the surfboard. More importantly, the fins can be installed in the fin box, and adjusted or removed from the fin box without the use of tools. By using the fin box installation system, manufacturers can effectively locate, align and install the fin box on the surfboard. More importantly, the manufacturers are able to lean and rotate the fins precisely at any desired angles and achieve precise and critical symmetrical mounting of the fins with relation to the centerline of the surfboard.

An inflatable floor for an inflatable boat acts as a keel using three inflatable floor layers. The uppermost first inflatable floor layer has a planar cross section. The second inflatable floor layer is located under the first inflatable floor layer. The third inflatable floor layer is located under the second inflatable floor layer. A plurality of threads are provided, in an X- or I-like configuration, inside air chambers of the three inflatable floor layers. The threads link the upper and lower walls of the air chamber of each respective inflatable floor layer to each other. The inflatable floor has increased buoyancy and stiffness, is easy to fold and transport and is easy and economical to repair or replace and thus is easily applicable to a large military or rescue inflatable boat.

A marine propulsion device is provided with a breakaway skeg having first and second attachment points. The first and second attachment points are configured to result in the second attachment points disengaging from a gear case or housing structure prior to the first attachment point. The attachment points can comprise open or closed slots and, when an open slot is used for the first attachment point, it can be provided with a first edge along which a first pin can exert a force along a preselected angle in response to an impact force on the skeg. The arrangement of attachment points allows a reaction force at the second pin to be predetermined in a way that assures the detachment of the skeg from the housing structure prior to the detachment of the housing structure from another structure, such as the boat hull, or transom.

A surfcraft fin system utilizing a rib between fin anchors. The rib sets the distance between the anchors eliminating the need for a manufacturing jig. The rib is removed during the surfcraft manufacturing process resulting in multiple fin anchors adhered into the surfcraft.

A boat hull comprises a hull body having two lateral flanks linked by a bottom surface, and at least two propulsion compartments provided in two bulges protruding below the bottom surface of the hull body. Each propulsion compartment lodges a propulsion engine located below the bottom surface of the hull body. The propulsion engines are located at the deepest position in the hull and below the water plane.

The invention relates to a method and apparatus for enhancing the heat transfer efficiency of a keel cooler by increasing the flow rate of coolant through the side tubes. Because the side tubes are exposed to a greater amount of fresh unhindered seawater, increasing the flow rate through the side tubes can have the effect of enhancing the overall heat transfer capability of the keel cooler. The invention relates to using apertures leading to the side tubes from the header and vice versa that are substantially arrow-shaped in design, wherein various benefits that lead to an increased flow rate are provided. The aperture is preferably symmetrically shaped so that a single die can be used to cut the aperture onto both side walls of the header.

An inflatable boat comprising: an inflatable float that is U-shaped and open at the stern, and that braced by a transom; a floor that is disposed inside the space defined by the float, and a V-shaped keel formed of a flexible canvas sheet fastened to the float and to the transom and tensioned by a longitudinal inflatable keel-forming spacer interposed between the floor and the canvas sheet; the inflatable keel-forming spacer is formed by at least two elongate and flat chambers inflated under a relatively high pressure; and the two chambers have their respective bottom longitudinal edges touching and their respective top longitudinal edges spaced apart from each other so that the keel-forming spacer is generally V-shaped in cross-section.

A fin for an recreational device including: a rigid fin core having opposite sides, at least one edge and a base; at least one registration post on each of the opposite sides of the core, and a flexible material at least partially covering the core, wherein the flexible material include leading and trailing fin edges extending outward from the edge of the core and the flexible material is flush with an end surface of each of the at least one registration post.

A pivotable deployable bulb mounted foil apparatus for a sailboat can pivot a foil mounted within a keel bulb remotely as needed to provide lateral resistance for the sailboat. The foil or foils can be rotated between a nested position for greater speed when the foils are not needed for lateral resistance in the water to an extended or operative position when needed for lateral resistance. The pivotal bulb mounted foil is especially adapted for use with a canting keel where the sailboat loses its lateral resistance from the keel when the keel is canted.

The invention relates to a dragon boat with frusta support type suspension base plates arranged in a boat body with integrated inner layer and outer layer, which is characterized in that the boat body comprises an integral liner, an integral outer shell and a boat board beam, the front end of the liner is provided with a boat head hanging groove, a boat channel card, caulking grooves of chairs and a drum position, the rear end of the liner is sequentially provided with a rudder position and a boat tail hanging groove, the inner walls of the both inner sides of the liner under a water line of the dragon boat are provided with base plate edges, the integral liner is arranged in the integral outer shell, the boat board beam is connected with the top parts of the integral outer shell and the integral liner to form the double-layer wall boat body with a head floating bin and a tail floating bin, the boat head hanging groove and the boat tail hanging groove are respectively articulated with a boat head and a boat tail, the frusta support type suspension base plates are distributed on the base plate edges of the liner, and both sides of the bottom center of each frusta support type suspension base plate are provided with double pedals. The dragon boat not only has reasonable design, compact structure and improved strength and rigidity, is not easy to deform, but is easy to manufacture and assemble and increases production efficiency, and the boat head and the boat tail are not easy to damage, are convenient to carry and have attractive appearance.

A windsurfing catamaran with a self-stabilizing wing. The wing is moved to the correct position by counter balancing water pressure from a rotating central keel connected to a central mast. The keel rotates in the opposite direction of the wing when the wing is moved off center by wind. The keel rotates such that a greater surface area is presented to water flow striking the keel. Water pressure on the keel offsets wind pressure on the sails and returns the keel and mast back to an upright position. This increases stability, lift, driving force, and speed. A central catamaran platform provides hinged struts and shock absorbers between the rear end of the central platform and planing hulls to reduce impact damage. The hinged struts and shock absorbers reduce water drag and the braking effect of repeated hull impacts with water resulting in a further increase in speed.

Keel or fin (1) for a watercraft such as a surfboard is conventional in shape but comprises major portion (2) fixed to the board by peg (10) and minor, flexible, trailing portion (3) fixed to major portion (2). Minor portion (3) has a more rigid leading edge (16) which slides dovetail fashion onto trailing edge (8, 9) of major portion (2) and is locked in place by grub screw (7). Minor portion (3) has core (11) of rubber allowing it to flex sideways under water pressure. Excessive movement of trailing edge (12) of minor portion (3) is prevented when edge (12) contacts stops (4) positioned on either side on the board. Minor portion (3) may be completely surrounded in an aperture in major portion (2) or may have apertures to which air is fed via ducting.