A drainage device for directing fluid away from a thru-hull fitting located on a hull of a vessel includes: a channel body mountable proximate to and extendable away from the hull of the vessel; a groove formed along at least a partial length of the thru-hull body; and a lip protruding from a bottom edge of the channel body at an end of the channel body that is distal from the hull of the vessel when the drainage device is mounted thereon.

A drainage device for directing fluid away from a thru-hull fitting located on a hull of a vessel includes: a channel body mountable proximate to and extendable away from the hull of the vessel; a groove formed along at least a partial length of the thru-hull body; and a lip protruding from a bottom edge of the channel body at an end of the channel body that is distal from the hull of the vessel when the drainage device is mounted thereon.

The present invention relates to a surface cover for a body which can be brought into contact with a liquid, comprising: a layer which at least partly contains gas and which is designed and arranged such that at least some sections of a layer face facing the liquid contacts the liquid; a gas-permeable layer which is arranged on the gas-containing layer on a face that faces the body and is opposite the face facing the liquid or which is integrally formed with the gas-containing layer; and a gas-supplying device which is connected to the gas-permeable layer such that gas can flow from the gas-supplying device to the gas-containing layer through the gas-permeable layer. The invention also relates to an arrangement and a use.

The present invention relates to a surface cover for a body which can be brought into contact with a liquid, comprising: a layer which at least partly contains gas and which is designed and arranged such that at least some sections of a layer face facing the liquid contacts the liquid; a gas-permeable layer which is arranged on the gas-containing layer on a face that faces the body and is opposite the face facing the liquid or which is integrally formed with the gas-containing layer; and a gas-supplying device which is connected to the gas-permeable layer such that gas can flow from the gas-supplying device to the gas-containing layer through the gas-permeable layer. The invention also relates to an arrangement and a use.

A transverse hydro-laminar flow system is a system that improves laminar flow across a watercraft's hull as the watercraft is moving through a body of water. The system may include air dispersal units, a first base anchor, a second base anchor, an air supply system, a controller, and a power system. The air dispersal units enable the creation of an air layer between the watercraft's hull and the surrounding water. The first base anchor and the second base anchor facilitate the fastening of the air dispersal units about the watercraft's hull without the need to dry dock the watercraft. The air supply system provides a constant air flow to each of the air dispersal units to enable the creation of the air layer that reaches most of the watercraft's hull. The controller enables the configuration of the system, while the power system supplies the necessary power for the system operation.

A transverse hydro-laminar flow system is a system that improves laminar flow across a watercraft's hull as the watercraft is moving through a body of water. The system may include air dispersal units, a first base anchor, a second base anchor, an air supply system, a controller, and a power system. The air dispersal units enable the creation of an air layer between the watercraft's hull and the surrounding water. The first base anchor and the second base anchor facilitate the fastening of the air dispersal units about the watercraft's hull without the need to dry dock the watercraft. The air supply system provides a constant air flow to each of the air dispersal units to enable the creation of the air layer that reaches most of the watercraft's hull. The controller enables the configuration of the system, while the power system supplies the necessary power for the system operation.

Disclosed are a method and a device for reducing the wave-making resistance and friction force during ship navigation. The device includes a gas-liquid mixing device and a control device that are connected. The gas-liquid mixing device is provided with a water inlet, a gas inlet, a water outlet, and a gas-liquid mixing cavity arranged between the water inlet and the water outlet. Water and gas enter the gas-liquid mixing cavity via the water inlet and the gas inlet respectively, the control device controls gas intake at the gas inlet, and in this process, the water inlet is controlled to intermittently suspend water intake or intermittently implement low-speed water intake or implement continuous low-speed water intake, so that more gas enters the gas-liquid mixing cavity.

Disclosed are a method and a device for reducing the wave-making resistance and friction force during ship navigation. The device includes a gas-liquid mixing device and a control device that are connected. The gas-liquid mixing device is provided with a water inlet, a gas inlet, a water outlet, and a gas-liquid mixing cavity arranged between the water inlet and the water outlet. Water and gas enter the gas-liquid mixing cavity via the water inlet and the gas inlet respectively, the control device controls gas intake at the gas inlet, and in this process, the water inlet is controlled to intermittently suspend water intake or intermittently implement low-speed water intake or implement continuous low-speed water intake, so that more gas enters the gas-liquid mixing cavity.

A reduced drag surface involves a perforated or porous surface exposed to a flowing fluid and a slip interface disposed between the surface and the flowing fluid, wherein the slip interface is formed from an entrapped fluid trapped at the surface. A method for modifying a drag coefficient on a reduced drag surface involves the steps of supplying a fluid to a perforated or porous surface exposed to a flowing fluid, wherein the surface traps the fluid at the surface to form an entrapped fluid and forming a slip interface between the surface and the flowing fluid, wherein the slip interface is formed from the entrapped fluid. An apparatus for a reduced drag surface includes the reduced drag surface described above and a source of fluid fluidically coupled to the surface such that the source supplied fluid to the surface to form the entrapped fluid.

A reduced drag surface involves a perforated or porous surface exposed to a flowing fluid and a slip interface disposed between the surface and the flowing fluid, wherein the slip interface is formed from an entrapped fluid trapped at the surface. A method for modifying a drag coefficient on a reduced drag surface involves the steps of supplying a fluid to a perforated or porous surface exposed to a flowing fluid, wherein the surface traps the fluid at the surface to form an entrapped fluid and forming a slip interface between the surface and the flowing fluid, wherein the slip interface is formed from the entrapped fluid. An apparatus for a reduced drag surface includes the reduced drag surface described above and a source of fluid fluidically coupled to the surface such that the source supplied fluid to the surface to form the entrapped fluid.