A rudder assembly, including a steering engine; an axial hollow rudder stock; a rudder blade; a gas release unit; and a tiller. The steering engine is disposed in a vessel stern. The tiller is connected to the steering engine. The axial hollow rudder stock includes a through hole. The through hole is small and disposed along the axis of the axial hollow rudder stock. The gas release unit is disposed in the vessel stern, and includes a control cabinet. The control cabinet includes a reagent storage tank, a reagent conveying hose connected to the reagent storage tank, a compressed air bottle, a pressure hose connected to the compressed air bottle, and a console. The pressure hose and the reagent conveying hose pass through the through hole of the axial hollow rudder stock, and then communicate with the cavity of the rudder blade.

A rudder assembly, including a steering engine; an axial hollow rudder stock; a rudder blade; a gas release unit; and a tiller. The steering engine is disposed in a vessel stern. The tiller is connected to the steering engine. The axial hollow rudder stock includes a through hole. The through hole is small and disposed along the axis of the axial hollow rudder stock. The gas release unit is disposed in the vessel stern, and includes a control cabinet. The control cabinet includes a reagent storage tank, a reagent conveying hose connected to the reagent storage tank, a compressed air bottle, a pressure hose connected to the compressed air bottle, and a console. The pressure hose and the reagent conveying hose pass through the through hole of the axial hollow rudder stock, and then communicate with the cavity of the rudder blade.

A pressurized air cushioned hull with fixed rigid side, front and rear seals. The hull includes a plurality of keels, with an air cushion disposed between inboard walls of each keel and an air cushion created/disposed along the outboard walls of each keel. These air cushions along the outboard walls of the keels are created by angling each keel by about 0.02 to about 1 relative to the longitudinal axis of the hull, wherein the left keel(s) is rotated clockwise and the right keel(s) is rotated counterclockwise, such that a distance between the keels is smaller at the front end of the keels than at the rear end of the keels. This slight angle was found to allow air, rather than water, to contact the outboard walls, unexpectedly reducing drag resistance a significant amount, thus improving performance of the hull as a whole.

A pressurized air cushioned hull with fixed rigid side, front and rear seals. The hull includes a plurality of keels, with an air cushion disposed between inboard walls of each keel and an air cushion created/disposed along the outboard walls of each keel. These air cushions along the outboard walls of the keels are created by angling each keel by about 0.02 to about 1 relative to the longitudinal axis of the hull, wherein the left keel(s) is rotated clockwise and the right keel(s) is rotated counterclockwise, such that a distance between the keels is smaller at the front end of the keels than at the rear end of the keels. This slight angle was found to allow air, rather than water, to contact the outboard walls, unexpectedly reducing drag resistance a significant amount, thus improving performance of the hull as a whole.

Device mountable on a surface (10), the device comprising a spacer system (12, 16, 20, 22) and a grid structure (2) which grid structure (2) is attached in spaced relation to the surface (10) by means of the spacer system (12, 16, 20, 22), wherein the distance between the surface (10) and the grid structure (2) is in a range from >0.1 m to <10 mm, wherein the grid structure (2) forms meshes of a mesh size in a range from >0.5 m to <8 mm, and wherein the surface of the grid structure (2) is at least partially amphiphobic. Method of maintaining a gas or air layer on a surface when the surface is immersed in a liquid or water comprising such device, and uses thereof.

Device mountable on a surface (10), the device comprising a spacer system (12, 16, 20, 22) and a grid structure (2) which grid structure (2) is attached in spaced relation to the surface (10) by means of the spacer system (12, 16, 20, 22), wherein the distance between the surface (10) and the grid structure (2) is in a range from >0.1 m to <10 mm, wherein the grid structure (2) forms meshes of a mesh size in a range from >0.5 m to <8 mm, and wherein the surface of the grid structure (2) is at least partially amphiphobic. Method of maintaining a gas or air layer on a surface when the surface is immersed in a liquid or water comprising such device, and uses thereof.

The present invention provides a vessel (10) comprising: a bow (100) having a port side and a starboard side, a pair of extended arms (101, 102) comprising: a port side extended arm (101) operationally coupled to the port side of the bow (100), and a starboard side extended arm (102) operationally coupled to the starboard side of the bow (100), the pair of extended arms (101, 102) configuring a trapezoidal zone and bifurcating an incoming wave towards the vessel (10) into three directions: towards port side, toward starboard side and a center wave into the trapezoid pool (103), thereby reducing impact of wave resistance on the vessel (10). The trapezoid pool (103) facilities the generation of air bubbles (500) by collisions of the center wave with the bow (100) and the pair of extended arms (101, 102).

The present invention provides a vessel (10) comprising: a bow (100) having a port side and a starboard side, a pair of extended arms (101, 102) comprising: a port side extended arm (101) operationally coupled to the port side of the bow (100), and a starboard side extended arm (102) operationally coupled to the starboard side of the bow (100), the pair of extended arms (101, 102) configuring a trapezoidal zone and bifurcating an incoming wave towards the vessel (10) into three directions: towards port side, toward starboard side and a center wave into the trapezoid pool (103), thereby reducing impact of wave resistance on the vessel (10). The trapezoid pool (103) facilities the generation of air bubbles (500) by collisions of the center wave with the bow (100) and the pair of extended arms (101, 102).

A low-cost viscous-drag-reducing cladding for a ship's hull comprising airbags whose outer surfaces are adapted to be water repelling. Each airbag comprises a plenum that comprises substantially open space, which does not obstruct the flow of air through it. The airbags are inflated with compressed air to a pressure higher than the adjoining hydrostatic pressure. The airbag material comprises a reinforcing fabric, which is adapted to withstand the forces encountered during operation, and is sealed with a sealant so as to be made substantially impermeable to air. The outer water-repelling surface of each airbag is connected to a plenum by means of restrictor holes. Air flows from the plenum through the restrictor holes into the water-repelling layer.

A low-cost viscous-drag-reducing cladding for a ship's hull comprising airbags whose outer surfaces are adapted to be water repelling. Each airbag comprises a plenum that comprises substantially open space, which does not obstruct the flow of air through it. The airbags are inflated with compressed air to a pressure higher than the adjoining hydrostatic pressure. The airbag material comprises a reinforcing fabric, which is adapted to withstand the forces encountered during operation, and is sealed with a sealant so as to be made substantially impermeable to air. The outer water-repelling surface of each airbag is connected to a plenum by means of restrictor holes. Air flows from the plenum through the restrictor holes into the water-repelling layer.