Catamaran boat hulls are described having sponsons, an underside tunnel surface between sponsons, two longitudinal steps disposed across each sponson's keel, and two transverse steps disposed lengthwise on opposing sides of each sponson's keel. The longitudinal steps for a sponson have a profile with a curved longitudinal step portion on the opposing outer edges with an outer edge portion of that curved longitudinal step portion being further away from the sponson's aft section, and an inward step edge offset where each of the two longitudinal steps meets a hull side of the sponson. The transverse steps help define variable deadrise inner lifting pad running portion with a lower deadrise aft transitioning to a higher deadrise forward. Spray rails protruding off the aft end of an underside wave spitter and away from the boat hull's centerline help manage undesired spray and use of radiused chines enhances lift and landing performance.

A ballast water-free ship using a difference in the depth of the bottom shell plate between the bow/stern and the midship section and a construction method thereof. A stepped portion is formed between either the bow or the stern and the midship section, such that the depth of the bottom shell plate of either the bow or the stern differs from the depth of the bottom shell plate of the cargo containment in the midship section, so that cargo can be loaded and unloaded without ballast water operation.

A ballast water-free ship using a difference in the depth of the bottom shell plate between the bow/stern and the midship section and a construction method thereof. A stepped portion is formed between either the bow or the stern and the midship section, such that the depth of the bottom shell plate of either the bow or the stern differs from the depth of the bottom shell plate of the cargo containment in the midship section, so that cargo can be loaded and unloaded without ballast water operation.

An objective of the present invention is to provide an underwater ship attachment that is used to divert air, debris, and pressure fluctuations. More specifically, the present invention discloses an anti-cavitation device (such as a diverter device) for flat-bottom boats. The air diverter has been developed to regain, enhance, and protect the operational function of propulsive and steering equipment among displacement and semi displacement hulls. As with protect items such as bottom mounted depth sounder transducers, intakes for engine or general cooling, sea chests, keel coolers, zincs, and all other underwater mounted items susceptible to air ingestion, air disturbance malfunction or debris impact.

An objective of the present invention is to provide an underwater ship attachment that is used to divert air, debris, and pressure fluctuations. More specifically, the present invention discloses an anti-cavitation device (such as a diverter device) for flat-bottom boats. The air diverter has been developed to regain, enhance, and protect the operational function of propulsive and steering equipment among displacement and semi displacement hulls. As with protect items such as bottom mounted depth sounder transducers, intakes for engine or general cooling, sea chests, keel coolers, zincs, and all other underwater mounted items susceptible to air ingestion, air disturbance malfunction or debris impact.

This disclosure describes hybrid chine hulls, marine vessels including hybrid chine hulls and methods of manufacturing and using hybrid chine hulls. An exemplary hybrid chine hull includes a keel, a single chine section, and a double chine section distinct from the single chine section with respect to a longitudinal direction of the keel and positioned aft of the single chine section.

This disclosure describes hybrid chine hulls, marine vessels including hybrid chine hulls and methods of manufacturing and using hybrid chine hulls. An exemplary hybrid chine hull includes a keel, a single chine section, and a double chine section distinct from the single chine section with respect to a longitudinal direction of the keel and positioned aft of the single chine section.

A ballast water-free ship using a difference in the depth of the bottom shell plate between the bow/stern and the midship section and a construction method thereof. A stepped portion is formed between either the bow or the stern and the midship section, such that the depth of the bottom shell plate of either the bow or the stern differs from the depth of the bottom shell plate of the cargo containment in the midship section, so that cargo can be loaded and unloaded without ballast water operation.

A ballast water-free ship using a difference in the depth of the bottom shell plate between the bow/stern and the midship section and a construction method thereof. A stepped portion is formed between either the bow or the stern and the midship section, such that the depth of the bottom shell plate of either the bow or the stern differs from the depth of the bottom shell plate of the cargo containment in the midship section, so that cargo can be loaded and unloaded without ballast water operation.

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.