The invention relates to a vessel (1) comprising a hull (2) for non-planing operation, during operation displaying a waterline (3) and having a forward direction in a horizontal plane (4) with a forward portion, an aft portion (5), and a central portion, the aft portion having a smaller water displacement relative to a water displacement of the central portion; and an aft, primary foil (6) affixed to the aft hull portion with a connecting member (7), configured to be below the waterline during operation, spaced from the hull, the aft foil having a span, a chord, a profile, a leading edge (8) and a trailing edge (9) relative to the forward direction, characterized by adjustment means (10) connected to the aft foil and configured for adjusting an angle of incidence (.sub.c, af) of the chord of the aft foil.

Provided is a hull of a boat including a central portion of a bottom of the hull, side portions of the bottom of the hull, lateral to the central portion of the bottom of the hull, the central portion of the bottom of the hull being substantially lowered in a substantially discontinuous way with respect to the side portions of the bottom of the hull, central side walls separating the central portion of the bottom of the hull from the side portions of the bottom of the hull. The hull also having external side walls laterally external to the side portions of the bottom of the hull.

The invention relates to boat building and can be used in the building and modification of sea-going high-speed keeled monohull sailboats or sail and motor boats with a high sail power to weight ratio, where a single, narrow, wave-penetrating displacement hull is used. To provide for the stable controlled movement of a keeled monohull sailboat or sail and motor boat in wave penetration mode, i.e. in a low wave/hydrodynamic resistance displacement mode, both when heeling and when upright (at the same time effectively counteracting heeling and rocking on all courses), and to provide for the damping of the energy of a broken wave and also for the ability of the boat to self-right to an even keel from a sail-on-water position, a stabilized hull for a keeled monohull sailboat or sail and motor boat is configured with an overall width of not more than 50% of the length of the hull and has, in the bottom part thereof, a vertically oriented narrow section (4) of low wave/hydrodynamic resistance, which runs longitudinally along the full length of the boat, is symmetrical about the centreline thereof and has a displacement segment (5) comprising a keel (8) with a heavy bulb, wherein the displacement of the segment is equal to the full unladen weight of the boat. The hull further comprises two narrow longitudinally oriented sponsons (6 and 7), arranged symmetrically in relation to the centreline of the boat, which do not bear the weight of the boat and which have a streamlined shape of low wave/hydrodynamic resistance. Said sponsons are situated above the waterline at the maximum width of the hull, forming two tunnel cavities (10) above the waterline to dampen the energy of a wave broken by the bow and the sponsons.

A system for enhancing a wake profile produced by a pontoon boat is provided. The system includes a pair of ramps attached to the bottom of a platform supported by at least two pontoons. The ramps may be oriented downward with a rear end of the ramp disposed in the water between the pontoons. The water flowing between the pontoons is displaced downward by the ramps, thereby increasing water displacement and directing the water to produce an improved wake profile. Downforce may be applied to the boat by one or more wake plates, with a faceted portion of the wake plate facing forward and upward, such that when water impacts the faceted portion a downforce is provided. The wake plates may be attached to the ramps or may be separate from the ramps.

A system for enhancing a wake profile produced by a pontoon boat is provided. The system includes a pair of ramps attached to the bottom of a platform supported by at least two pontoons. The ramps may be oriented downward with a rear end of the ramp disposed in the water between the pontoons. The water flowing between the pontoons is displaced downward by the ramps, thereby increasing water displacement and directing the water to produce an improved wake profile. Downforce may be applied to the boat by one or more wake plates, with a faceted portion of the wake plate facing forward and upward, such that when water impacts the faceted portion a downforce is provided. The wake plates may be attached to the ramps or may be separate from the ramps.

The novel bladder systems and tie down systems set forth herein provide systems and apparatuses that mitigate or prevent damage, such as tipping over/capsizing, of a watercraft stored on shore or an aircraft secured to a ground surface during adverse wind, rising water, or storm events. Further, novel apparatuses and methods for storing a watercraft using the bladders as cushioning or holding devices when installed within a cavity, whether the cavity is created by digging a hole or building an enclosing berm, provides additional stability and security for the watercraft during adverse wind, rising water, or storm events.

A marine vessel comprising: at least one buoyant tubular foil; and at least one baffle plate positioned about the perimeter of the at least one buoyant tubular foil so as to protrude into the flow of water passing by the perimeter of the at least one buoyant tubular foil, whereby to create a high-pressure zone fore of the at least one baffle plate and a low-pressure zone immediately aft of the at least one baffle plate, whereby to create a dense stream of supercavitated water immediately aft of the at least one baffle plate.

A marine vessel comprising: at least one buoyant tubular foil; and at least one baffle plate positioned about the perimeter of the at least one buoyant tubular foil so as to protrude into the flow of water passing by the perimeter of the at least one buoyant tubular foil, whereby to create a high-pressure zone fore of the at least one baffle plate and a low-pressure zone immediately aft of the at least one baffle plate, whereby to create a dense stream of supercavitated water immediately aft of the at least one baffle plate.

The invention relates to a vessel (1), especially a drillship or so-called drilling ship. The vessel comprises a hull (3) having a bottom surface (5) and a deck (7). Said vessel is provided with a moon pool (2), which extends from said bottom surface of the hull in an upward direction through the hull. Further, said vessel is provided with a cavity (10) located at a front side of the moon pool. Said cavity is at least partly open at a bottom side thereof in order to allow water to flow into said cavity. Moreover, said cavity is at least partly open at a rear side of said cavity in order to allow water to flow directly from said cavity into the moon pool, as a result of which moon pool sloshing can be diminished and the mean flow resistance of the vessel when sailing can be reduced.