A boat comprising a wake shaping system comprising starboard and port wake shaping devices located aft of the transom. Each wake shaping device is operable to move between a first, non-deployed position behind the transom and a second, deployed position extending outside the side of the hull or below the transom. When the starboard wake shaping device is in the deployed position, a port wakesurf wake is created. When the port of the wake shaping device is in the deployed position, a starboard wakesurf wake is created. When neither wake shaping device is deployed, a symmetrical wakeboard wake is created.

The present invention provides, with reference to FIG. 2, an amphibian operable in land and marine modes, the amphibian comprising a hull, at least one discontinuity (wheel bay) provided in the hull, and at least one retractable wheel or track assembly at least partially located in the at least one discontinuity (wheel bay). The hull is a planing hull, and the at least one discontinuity (wheel bay) is provided in the front half of the hull of the amphibian. The amphibian further comprises at least one conduit which opens, or is provided with an entry which opens, into or at the at least one discontinuity (wheel bay) and is configured for channelling, in use, fluid away from the at least one discontinuity (wheel bay).

Systems and associated methods for rapid integration and control of payloads carded by a multi-mode, unmanned vehicle configured to accommodate a variety of payloads of varying size, shape, and interface and control characteristics. Mechanical, power, signal, and logical interfaces to a variety of payloads operate to enable environmental protection, efficient placement and connection to the vehicle, and control of those payloads in multiple environmental modes as well as operational modes (including in air, on the surface of water surface, and underwater).

A method of operating a boat to produce a surf wake includes partially filling a transverse ballast tank, moving the boat through a body of water, rolling the boat toward either its port or starboard side to shift the water in the transverse ballast tank such that at least some of the water in the transverse ballast tank moves from one side of a longitudinal centerline of the boat to the other side of the centerline, and creating a surf wake on the side toward which the boat is rolled.

The invention relates to an arrangement for multi screw vessels, in particular twin screw vessels, with external propeller shafts, as well as to a method for producing such an arrangement. The arrangement according to the invention is in particular suitable for a drive system of an above-mentioned multi screw vessel and to improve the energy efficiency thereof.

A three stage watercraft for operation in the water as a traditional boat at low speeds in stage one, for operation on the water's surface at mid-range speeds at stage two, and for traveling in ground effect at higher range speeds is disclosed. The three stage craft includes a hydro-wing 12, at least a single hydrofoil 13 to aid with lift from stage one to stage two, and a pair of outboard floats or hydro-floats 16a, 16b supported by the hydro-wing 12, which are also designed to aid with lift from stage one to stage two. A gyration rotor 14 to aid with lift from stage one to stage two may also be provided as may a pair of pivotally mounted air propellers which aid in lift and propulsion by varying their operational angle relative to the plane of travel of the craft.

Ships for navigating in icy waters having improved propulsion performance in open water and at the same time good maneuverability forward in icy waters are provided. Such ships include those having a bow area with a bulb adapted to generate a bow wave in phase opposition with respect to that generated by the ship's hull.

A method and a system for controlling a marine vessel having first and second trim deflectors is disclosed. The first and second trim deflectors have a first surface having a first area and a second surface having a second area, wherein the second planar surface is coupled to the first surface. The method and system control the first and second trim deflectors to induce any of a net yawing force, a net rolling force, and a net trimming force to the marine vessel without inducing any other substantial forces to the marine vessel by controlling the first and second trim deflectors.

An apparatus including a fine-array porous material with a specific surface area higher than 10/mm, the specific surface area depending on different pore sizes, wherein the porous material comprises a plurality of pores having a substantially uniform size with a variation of less than about 20%, wherein the size is larger than about 100 nm and smaller than about 10 cm. The high-buoyancy apparatus can be part of a water vehicle such as a boat or a submarine, and the fine-array porous material is configured to reduce friction and/or control buoyancy. A conduit is also provided employing a fine-array porous material to reduce friction and/or control buoyancy. A garment is provided taking advantage of water repellant and/or UV/IR reflection properties of the fine-array porous material.

A device for reducing frictional resistance includes: a chamber which is provided to a draft part of a hull and in which blowing holes blowing out air into the water of the outside of the hull from different positions to each other in a height direction of the hull are formed; a supply pipe supplying the air to an internal space of the chamber; and a distributor provided to each of the blowing holes, and guiding a part of the air, which was supplied inside the chamber from the supply pipe, to each of the blowing holes. The plurality of distributors has a flow-amount adjuster adjusting a flow amount of the air guided to the blowing hole corresponding to each of the distributors so that the flow amount of the air blown out from the plurality of blowing holes is equalized in each of the blowing holes.