A multihull sailing vessel includes at least two buoyant hulls extending along their longitudinal axes, with the hulls being connected to each other and a first hydrofoil connected to the hulls and oriented transverse to the hulls. The first hydrofoil is movably coupled to the hulls between a first position above a resting waterline of the hulls and a second position below a lowest extent of the hulls. When the first hydrofoil is in the second position, a configuration of the first hydrofoil is adjustable to vary an amount of lifting force generated by the first hydrofoil when the hulls move forward through water when the first hydrofoil is in the second position.

The present invention provides a catamaran centralized-transportation fishing ship and a control method, which relate to the technical field of fishing of fishing ships. The catamaran centralized-transportation fishing ship has the fishing assembly and the concave chamber for centralized transportation of fish bodies, which can simultaneously have two functions of fishing and centralized transportation, and has a wide application range. Compared with existing fishing ships for fishing operations, the fishing ship can place the caught fish bodies in the concave chamber, so that the fish bodies can be in original water quality during a transfer process, and thus a survival rate of the fish bodies is increased. Meanwhile, setting of the limiting mechanism can prevent the fish bodies from escaping and increase a fishing amount of a single fishing operation.

An unmanned, autonomous, ocean-going vessel including a primary hull and a rigid wing rotationally coupled with the primary hull that freely rotates about a rotational axis. At least one of the primary hull and the rigid wing includes at least one selectively floodable compartment configured to selectively flood to submerge the primary hull and at least a portion of the rigid wing. The vessel further includes at least one controller configured to maintain a desired heading. The vessel further includes a control surface element configured to aerodynamically control a wing angle of the rigid wing based on a force exerted by wind on the control surface element. The vessel further includes a rudder. The at least one controller is further configured to determine a rudder position and generate a signal to position the rudder. The vessel further includes a keel coupled with the primary hull.

An unmanned, autonomous, ocean-going vessel including a primary hull and a rigid wing rotationally coupled with the primary hull that freely rotates about a rotational axis. At least one of the primary hull and the rigid wing includes at least one selectively floodable compartment configured to selectively flood to submerge the primary hull and at least a portion of the rigid wing. The vessel further includes at least one controller configured to maintain a desired heading. The vessel further includes a control surface element configured to aerodynamically control a wing angle of the rigid wing based on a force exerted by wind on the control surface element. The vessel further includes a rudder. The at least one controller is further configured to determine a rudder position and generate a signal to position the rudder. The vessel further includes a keel coupled with the primary hull.

A jet pump assembly includes a marine engine, a jet drive and a shield adapted to be secured to a transom of a watercraft. The shield has arms to which the marine engine is secured and legs to which an intake mount is secured. The jet drive is supported by the intake mount. The shield has at least one flange adapted to be secured to a middle toon of a pontoon boat. The shield covers an opening in the middle toon through which the marine engine is passed during assembly. A gasket between the shield and opening prevents water from entering the middle toon.

A catamaran for a wheelchair has two parallel pontoons secured abeam a bow beam and a wheelchair engaging framework for selective attachment and submersion of a wheelchair in water between the pontoons behind the bow beam in use. The catamaran is able to engage a wheelchair in a simple and convenient manner for recreational water sport use by those of limited mobility.

A catamaran for a wheelchair has two parallel pontoons secured abeam a bow beam and a wheelchair engaging framework for selective attachment and submersion of a wheelchair in water between the pontoons behind the bow beam in use. The catamaran is able to engage a wheelchair in a simple and convenient manner for recreational water sport use by those of limited mobility.

A pontoon boat is provided that includes at least two pontoons running longitudinally beneath the boat and providing buoyancy thereto; a deck framework mounted above and connected to the pontoons; a deck mounted on the deck framework; a recessed deck portion extending downwardly through the deck and the deck framework, the recessed deck portion forming a cavity into the deck including a bottom and side walls forming a basin extending into and beneath the deck; and at least one seat adjacent the recessed deck portion and mounted to the deck.

Embodiments include a retrofit pontoon system including a pontoon, the pontoon having a pontoon body defining a first cavity, a retrofit assembly, the retrofit assembly including a first lateral tube, wherein the first lateral tube is sized to pass through a first aperture formed in the pontoon body and a selectively fillable container, where the first lateral tube is operably coupled with the selectively fillable container, a main tube, where the main tube is fluidly coupled with the first lateral tube, and a pump, the pump being coupled with the main tube such that operation of the pump selectively fills and drains water from the selectively fillable container, where filling the selectively fillable container lowers the profile of the pontoon in the water and emptying the selectively fillable container raises the profile of the pontoon in the water.

A marine catamaran craft, comprising at least one forward hydrofoil fixed to each of the catamaran hulls and at least one rear hydrofoil in which: At least one forward hydrofoil is arranged for shallowly submerged operation At least one rear hydrofoil is arranged for shallowly submerged operation at low speeds and for planing operation at higher speeds A rear part of each of the catamaran hulls remains wetted at all speeds.