A hull auxiliary mechanism for reducing a draft of a hull, includes a guide baffle on both sides of the hull. Two ends of the guide baffle extend out of a front end and a rear end of the hull. A Lower end of the guide baffle extends out of a bottom of the hull. The front end and the rear end of the hull are flat inclined plates. The bottom of the hull is a flat plate; the hull auxiliary mechanism also includes a water resistance mechanism, and the water resistance mechanism includes a first diversion pressure plate, a second diversion pressure plate and a third diversion pressure plate. Both sides of the guide baffle are used to direct a flow of water to the hull. At the same time, there are three groups of diversion pressure plates at the bottom of the hull.

The underwater vehicle with variable configuration (1) comprises: a hull (2) consisting of at least four elongated elements (20), mutually articulated by means of joints (21), to form a first closed polygonal structure (F1), arranged on a plane; thrusters (3), associated in parallel with said elements (20) of the hull (2); actuating means (22), associated with said joints (21), provided for automatically modifying said first closed polygonal structure (F1), from an elongated shape configuration (AF1) to an expanded shape (EF1), corresponding to an elongated conformation of said hull (2), to determine a low hydrodynamic resistance and a longitudinal thrust of the thrusters (3) in the cruising of said underwater vehicle (1), and to a substantially isotropic conformation, wherein the same elements (20) of the hull (2), as well as the thrusters (3) are mutually angled, intended for the hovering of the same underwater vehicle (1), respectively. The latter can be suitably equipped with robotic arms (4) intended for performing maintenance or similar interventions in underwater locations.

A hull auxiliary mechanism for reducing a draft of a hull, includes a guide baffle on both sides of the hull. Two ends of the guide baffle extend out of a front end and a rear end of the hull. A Lower end of the guide baffle extends out of a bottom of the hull. The front end and the rear end of the hull are flat inclined plates. The bottom of the hull is a flat plate; the hull auxiliary mechanism also includes a water resistance mechanism, and the water resistance mechanism includes a first diversion pressure plate, a second diversion pressure plate and a third diversion pressure plate. Both sides of the guide baffle are used to direct a flow of water to the hull. At the same time, there are three groups of diversion pressure plates at the bottom of the hull.

A watercraft according to the present disclosure may include an outer hull that defines an interior or hull cavity, and a ballast system located within the hull cavity. The ballast system may include at least three ballast tanks longitudinally distributed along the hull cavity, and each of the tanks being configured to be independently operated enabling selective entrapment of ballast at three or more different longitudinal locations to enable an intentional shifting of the longitudinal center of gravity (LCG) of the watercraft relative to the design location of the LCG of the watercraft. The watercraft may include at least a forward, a center, and an aft ballast tank, and in some embodiments, additional tanks, in some cases in sponsons, may be included and/or one or more of the forward, center and aft tanks, may be further subdivided for additional active LCG control.

A marine vessel or watercraft may be provided with an aft extension that, in one configuration of the watercraft, alters the wake of the watercraft, for example by reducing the height of the wake, and which may include a sealable opening to provide crew or payload access into or out of the watercraft at a location (e.g., aft of the transom) that may be difficult for an observer to perceive. The aft extension may be positioned above the watercraft's waterline when the watercraft is in another configuration such that it does not contact with the water to reduce adverse impact on performance characteristics, such as drag, of the hull when the watercraft is in that configuration. The watercraft may transition between the two configuration by selectively varying the displacement of the watercraft or by articulating of the aft extension.

In various embodiments, a wake diversion system operates to manipulate the characteristics of the stern waves produced by a watercraft as it passes through water. In one embodiment, the wake diversion system includes a wake diverter that is comprised of a body, a panel, and a plurality of boat attachment mechanisms. The wake diverter is removably attachable to the side of the hull of a watercraft such that it obstructs the natural flow of water around the hull of the watercraft on side of the watercraft to which it is attached.

A hull locating arrangement for a vessel is disclosed that has a body at least partially suspended above at least a first hull by at least one support. The hull locating arrangement includes for the first hull a forward locating linkage and a rearward locating linkage, each of the forward locating linkage and the rearward locating linkage being connected between the first hull and the body to together constrain said hull in the lateral, longitudinal, roll and yaw directions relative to the body. The forward locating linkage includes a forward radius arm and a drop link, the drop link being pivotally connected to the radius arm. The rearward locating linkage includes a rearward radius arm connected between the body and the first hull.

The underwater vehicle with variable configuration (1) comprises: a hull (2) consisting of at least four elongated elements (20), mutually articulated by means of joints (21), to form a first closed polygonal structure (F1), arranged on a plane; thrusters (3), associated in parallel with said elements (20) of the hull (2); actuating means (22), associated with said joints (21), provided for automatically modifying said first closed polygonal structure (F1), from an elongated shape configuration (AF1) to an expanded shape (EF1), corresponding to an elongated conformation of said hull (2), to determine a low hydrodynamic resistance and a longitudinal thrust of the thrusters (3) in the cruising of said underwater vehicle (1), and to a substantially isotropic conformation, wherein the same elements (20) of the hull (2), as well as the thrusters (3) are mutually angled, intended for the hovering of the same underwater vehicle (1), respectively. The latter can be suitably equipped with robotic arms (4) intended for performing maintenance or similar interventions in underwater locations.

A marine vessel or watercraft may be provided with an aft extension that, in one configuration of the watercraft, alters the wake of the watercraft, for example by reducing the height of the wake, and which may include a sealable opening to provide crew or payload access into or out of the watercraft at a location (e.g., aft of the transom) that may be difficult for an observer to perceive. The aft extension may be positioned above the watercraft's waterline when the watercraft is in another configuration such that it does not contact with the water to reduce adverse impact on performance characteristics, such as drag, of the hull when the watercraft is in that configuration. The watercraft may transition between the two configuration by selectively varying the displacement of the watercraft or by articulating of the aft extension.

A watercraft according to the present disclosure may include an outer hull that defines an interior or hull cavity, and a ballast system located within the hull cavity. The ballast system may include at least three ballast tanks longitudinally distributed along the hull cavity, and each of the tanks being configured to be independently operated enabling selective entrapment of ballast at three or more different longitudinal locations to enable an intentional shifting of the longitudinal center of gravity (LCG) of the watercraft relative to the design location of the LCG of the watercraft. The watercraft may include at least a forward, a center, and an aft ballast tank, and in some embodiments, additional tanks, in some cases in sponsons, may be included and/or one or more of the forward, center and aft tanks, may be further subdivided for additional active LCG control.