Abstract: A gearbox dampening system configured to absorb axial movement of the crank of the airboat engine to reduce damage causing vibration and noise is disclosed. The gearbox dampening system enables a gearbox to be releasably coupled to outer support structures of an engine to support the gearbox and enables one or more gears of the gearbox to be in communication with a crank of an airboat engine via one or more dampeners. In at least one embodiment, the one or more dampeners significantly reduces stresses imparted on the gears of the gearbox via axial movement of the crank of the engine created when the engine is running. In particular, axial movement of the crank of the engine, which would usually create noise, chatter and engine damage, is absorbed by the dampeners positioned between the crank and the one or more gears in the gearbox supporting an airboat propeller.

Abstract: Systems and methods to provide a watercraft fin box with a retractable fin. The fin box may be fitted to a watercraft such as an inflatable paddle board. The retractable fin is associated with a lever that allows the retractable fin to rotate within a body of the fin box. An elastic member positioned within the body of the fin box operates to urge the retractable fin away from the body when the retractable fin rotates into the body. The elastic member does not urge the retractable fin away from the body when the fin box is fitted to a watercraft and the retractable fin of the fin box is positioned to face the Earth, such as when the watercraft is placed atop water with the retractable fin immersed in water.

Abstract: A davit crane that includes a base adapted to operably engage with a ground surface. The davit crane also includes a drive assembly operably engaged with the base. The davit crane also includes an actuation assembly operably engaged with the drive assembly, wherein the actuation assembly is configured to move between a lowered position and a raised position via the drive assembly. The davit crane also includes a boom assembly operably engaged with the actuation assembly. The actuation assembly of the davit crane is operable to pivotably adjust the boom assembly between the raised position and the lowered position.

Abstract: A personal watercraft includes a ship body and a recovery water passage. The ship body includes a deck and a hull. The recovery water passage is provided in the hull, and includes a water intake opening through which water can be taken in when the ship body plains on a water surface, and a discharge opening through which the taken water is discharged. The recovery water passage is formed with a filter accommodation space that accommodates a filter that traps minute foreign matters contained in water flowing through the recovery water passage.

Abstract: Apparatuses are for removably supporting a marine drive on a marine vessel. The apparatuses have a transom bracket assembly having a swivel cylinder, a steering bracket assembly having a swivel tube disposed in and steerable relative to the swivel cylinder through a steering range, the steering range being delimited by opposing steering stops, wherein the transom bracket assembly comprises annular mouth configured so that as the swivel tube is inserted into the swivel cylinder, the steering bracket assembly operably engages the annular mouth and is thereby caused to rotate into alignment with the steering range.

Abstract: The subject matter of this specification can be embodied in, among other things, a method of submersible deployment that includes submersing a submersible turbine toward an anchor seated along a bottom of a body of water so that tail portion of the submersible turbine is oriented closer to a cap of the anchor and upstream of a nose portion of the submersible turbine, urging the submersible turbine against a direction of flow of the body of water such that a channel defined along a ventral portion of the submersible turbine is drawn over a cap of the anchor, and while the cap is slidably engaged the submersible turbine, rotating the submersible turbine about the cap such that the nose portion is oriented upstream of the tail portion.

Abstract: Disclosed is a method and system to provide protection for maritime vessels from multiple threat types including shoulder launched rocket propelled threats, ballistic (howitzer), and larger scale missile systems. According to an exemplary embodiment, the protection system is based on the ballistic launch (from the protected vessel) of an explosive charge(s) aimed ˜5 meters away from the vessel and ˜1 meter beneath the waterline followed by detonation to enable the formation of a water wall. Through the formation of a water wall, incident threats can be initiated (piezo fuze) and passivated through dynamic interaction with the water formation. In addition, the upward velocity of the water wall can enable an upwards rotation of the incident threat changing the orientation of the warhead jet formation (for shape charge warheads) above the vessel.

Abstract: A weight release device capable of being operated in deep sea without accompanying a mechanical operation. The weight release device includes a housing fixed to the underwater observation device; a thread made of thermoplastic resin; electric heater portions; a weight support plate; a locking member of the thread made of the thermoplastic resin; and a ring for hanging the weight. The thread made of the thermoplastic resin is arranged from a start point housed in the housing, arranged to pass through the first electric heater portion, locked to the locking member of the thread made of the thermoplastic resin, arranged to pass through the second electric heater portion housed in the housing, and returned to an end point housed in the housing. The weight is released only by conducting an electricity through the electric heater portion to release the weight for floating the underwater observation device.

Abstract: A propulsion unit for a marine vessel, including a shell structure, a shaft rotatably coupled to a propulsion motor inside the shell structure, and a propeller coupled to the shaft outside the shell structure. A shaft seal arrangement is provided to engage the shaft, such that at least a first seal chamber is delimited between adjacent seal lips and the shaft. A first lubrication arrangement is provided for circulating a first lubricant through the first seal chamber. The first lubrication arrangement further includes a first lubricant heat exchanger arranged at least partly outside of the shell structure for conducting the first lubricant therethrough and for transferring heat from the first lubricant to an outside environment of the shell structure.

Abstract: An exemplary fuel cell ship is a fuel cell ship for propelling a hull by using electric power supplied from a fuel cell that generates electric power through an electrochemical reaction of fuel, and includes a tank compartment installed therein with a fuel tank that stores the fuel. The tank compartment is provided below a deck of the hull and provided separately from other compartments.

Abstract: A pleasure craft is provided in which one or more decks of the craft have a deck construction in which a base body is provided, and in which a first part of supporting and stiffening members is arranged on an upper face of the base body, and a second part of the supporting and stiffening members is arranged on a lower face of the base body. This construction optimizes and rationalizes the arrangement of components of the installations of the craft in terms of size, weight and the required amount of space, as well as in terms of required power, this resulting in a reduction of time and cost for mounting the installations of the craft.

Abstract: The present invention relates to a storage tank for liquid hydrogen, comprising a wall, a base, which closes the wall at the end face on one side, a top, which closes the wall at the end face on the side facing away from the base, and an intermediate wall, which is arranged inside of the wall and at a distance therefrom, wherein a gap is provided between a lower edge of the intermediate wall and the base, so that an interior enclosed by the intermediate wall is fluidically connected to an interior enclosed by the wall.

Abstract: An exemplary fuel cell ship is a fuel cell ship for propelling a hull by using electric power supplied from a fuel cell that generates electric power through an electrochemical reaction of fuel, and includes a compartment including an emission source of the fuel and a first detector arranged in the compartment to detect the fuel. If the first detector detects that a concentration of the fuel in the compartment is equal to or greater than a first threshold value, a power supply to a non-explosion-proof device in the compartment is stopped.

Abstract: An outboard motor includes a first case accommodating an engine and an upper housing below the first case. At least a portion of an exhaust passage is in the upper housing and extends downward from the engine. A second case is below the upper housing. The second case includes a torpedo portion, an exhaust inlet, an exhaust outlet, and an exhaust chamber. The torpedo portion includes an internal space and a rear end. A propeller shaft is in the internal space of the torpedo portion. The rear end of the torpedo portion is forward of at least a portion of the exhaust passage as seen in a side view. The exhaust passage is connected to the exhaust inlet. The exhaust outlet communicates with the internal space of the torpedo section. The exhaust chamber communicates the exhaust inlet with the exhaust outlet.