The invention is a watercraft with at least one hull which creates hydrodynamic lift by using narrowing concave channels (1) on the underside of the said at least one hull where propulsion (3) is placed such that the said propulsion draws water through the said narrowing concave channels (1).

The invention is a watercraft with at least one hull which creates hydrodynamic lift by using narrowing concave channels (1) on the underside of the said at least one hull where propulsion (3) is placed such that the said propulsion draws water through the said narrowing concave channels (1).

A novel hull form is described consisting of a base hull that incorporates flared sides along a bow, middle, and stern sections with raked bow and stern stem lines. The bow and stern sections have lateral oriented shapes, either as an attachment or integral to the hull, spanning the hull beam. The cross sections of these shapes have a novel and specific geometric relationship in conjunction with the base hull to provide a constant cross sectional area between the forward and aft perpendiculars. The shape improves the powering and seakeeping of the vessel hull in the marine environment.

A novel hull form is described consisting of a base hull that incorporates flared sides along a bow, middle, and stern sections with raked bow and stern stem lines. The bow and stern sections have lateral oriented shapes, either as an attachment or integral to the hull, spanning the hull beam. The cross sections of these shapes have a novel and specific geometric relationship in conjunction with the base hull to provide a constant cross sectional area between the forward and aft perpendiculars. The shape improves the powering and seakeeping of the vessel hull in the marine environment.

An engine room arrangement for a marine vessel comprises a fin formed at a rear portion of a hull of the vessel. The fin projects downward from the hull and protects a propeller of the vessel. A gear box is arranged at least in part in the fin and transmits a rotation of a propulsion shaft coupled to a main engine to a propeller shaft drivably coupled to the propeller. The fin provides extra buoyancy for the vessel. The propeller shaft is formed as a relatively short shaft, while the propulsion shaft is formed as a high speed/low torque shaft having a smaller diameter.

An engine room arrangement for a marine vessel comprises a fin formed at a rear portion of a hull of the vessel. The fin projects downward from the hull and protects a propeller of the vessel. A gear box is arranged at least in part in the fin and transmits a rotation of a propulsion shaft coupled to a main engine to a propeller shaft drivably coupled to the propeller. The fin provides extra buoyancy for the vessel. The propeller shaft is formed as a relatively short shaft, while the propulsion shaft is formed as a high speed/low torque shaft having a smaller diameter.

The invention relates to a vessel for operating on a body of water comprising: a non-planing hull having a waterline and a longitudinal direction with a forward portion, an aft portion, and a central portion, the hull being configured to have the aft portion with a smaller water displacement relative to a water displacement at the central portion; and an aft foil affixed to the aft hull portion with one or more connecting members, and below the surface of the water, and spaced from the hull, the aft foil having a span, a chord, and a leading edge and a trailing edge relative to a forward direction, wherein the leading edge of the aft foil is tilted at a downward angle relative to the horizontal, wherein the aft foil has a chord and profile in longitudinal cross section, with a configuration to provide a lifting force, the tilt angle of the chord of the aft foil being measured with respect to the horizontal, and wherein the aft foil is oriented to provide a continuous, upward, forwardly directed component of the lifting force.

The invention relates to a vessel for operating on a body of water comprising: a non-planing hull having a waterline and a longitudinal direction with a forward portion, an aft portion, and a central portion, the hull being configured to have the aft portion with a smaller water displacement relative to a water displacement at the central portion; and an aft foil affixed to the aft hull portion with one or more connecting members, and below the surface of the water, and spaced from the hull, the aft foil having a span, a chord, and a leading edge and a trailing edge relative to a forward direction, wherein the leading edge of the aft foil is tilted at a downward angle relative to the horizontal, wherein the aft foil has a chord and profile in longitudinal cross section, with a configuration to provide a lifting force, the tilt angle of the chord of the aft foil being measured with respect to the horizontal, and wherein the aft foil is oriented to provide a continuous, upward, forwardly directed component of the lifting force.

Rear boat extensions for boats and boats having such are provided. The rear boat extensions described herein are generally suitable for boats comprising a transom and a plate that is pivotally mounted via a hinge near a bottom edge of the transom, such that the plate is pivotable about an axis of the hinge upwardly toward and downwardly away from the transom. In some embodiments, the rear boat extensions described herein may include a bottom surface including a recess and one or more sloped or curved sections disposed on either side of the recess. The recess is disposed at a front end of the rear boat extension and configured to accommodate pivoting of the plate beneath the bottom surface of the rear boat extension. The sloped or curved sections disposed on either side of the recess serve to push water toward respective outboard sides of the boat to manipulate the size and/or shape of the wake produced by the boat.

Rear boat extensions for boats and boats having such are provided. The rear boat extensions described herein are generally suitable for boats comprising a transom and a plate that is pivotally mounted via a hinge near a bottom edge of the transom, such that the plate is pivotable about an axis of the hinge upwardly toward and downwardly away from the transom. In some embodiments, the rear boat extensions described herein may include a bottom surface including a recess and one or more sloped or curved sections disposed on either side of the recess. The recess is disposed at a front end of the rear boat extension and configured to accommodate pivoting of the plate beneath the bottom surface of the rear boat extension. The sloped or curved sections disposed on either side of the recess serve to push water toward respective outboard sides of the boat to manipulate the size and/or shape of the wake produced by the boat.