The present disclosure provides in at least one embodiment a rotatable keel skirt assembly on a rectangular-shaped keel pontoon. The rectangular-shaped keel pontoon reduces the maximum hull width by a significant percentage compared to a circular-shaped keel pontoon while maintaining the same hull motion performance. The rotatable keel skirt assembly allows the size of the pontoon to define the width of the hull during some fabrication phases of the platform, rather than the additional width of the keel skirt assembly. Thus, the outreach of the crane and other equipment can be effectively used as if the keel skirt assembly was not present. After fabrication, the hull can be moved away from the quayside and the keel skirt assembly can be rotated into position for service. Various systems and methods are disclosed for articulating the keel skirt assembly about the hull.

Disclosed is a vessel with two watertight flaps attached in a tensioned state on the two sides of the longitudinal keel, each being under one of the two rear side portions of the V-shaped hull, the outer side edge of each flap being connected under the shell covering the bottom compartment on the same side, and the bottom side edge being connected to the bottom along a line which is angled from the rear to the front and angled toward the lower compartment, with a flap width tapering from the tensioned, free rear edge between the ends at the transom, toward a front portion connected to the bottom and/or to the shell at the connection between the upper and lower compartments, defining, with the latter and the bottom, a channel converging from front to rear and angled toward the rear end of the edge of the V-shaped craft hull.

Disclosed is a vessel with two watertight flaps attached in a tensioned state on the two sides of the longitudinal keel, each being under one of the two rear side portions of the V-shaped hull, the outer side edge of each flap being connected under the shell covering the bottom compartment on the same side, and the bottom side edge being connected to the bottom along a line which is angled from the rear to the front and angled toward the lower compartment, with a flap width tapering from the tensioned, free rear edge between the ends at the transom, toward a front portion connected to the bottom and/or to the shell at the connection between the upper and lower compartments, defining, with the latter and the bottom, a channel converging from front to rear and angled toward the rear end of the edge of the V-shaped craft hull.

A boat hull with port and starboard side walls that are vertical in cross section while the bottom of the hull immediately prior to the commencement of the stern part there-after is horizontal in cross section. Extending throughout the buoyant hulls stem part a longitudinally rectangular flat plate with port and starboard upwardly extending side walls, one each side, are located throughout the length of the vessels stem part. An upwardly directed second rectangular flat plate is arranged fore/aft extends midway between the afore side walls to a height in excess of the side walls. This upstanding plate butts its lowermost edge onto the mid-line of the first plate. Linking the forward edge of the longitudinally rectangular plate to the buoyant hull at its aftmost and deepest point are hinges.

An apparatus and method for control of at least one of a plurality of semiautonomous marine vessels are provided. The system includes a control station with a communications system for network communication with marine vessels, and provides diagnostics and control for control and monitoring of the marine vessels, according to a mission plan.

A boat hull or other marine structure is made by shaping a plastic foam core and covering it with a plastic outer skin glued in place by adhesive, mechanically fastened, or applied in liquid form. Minimal sawcuts to the foam core ease manufacture. Methods for anchoring fittings, masts, pipes and shade canopies are presented. No-sew sails for the boat have corners made of plastic sheet attached using both adhesive and mechanical fastening. Lateral resistance of the hull is provided by telescoping leeboards. A suite of these boats share the same modular masts and sails. Such boat hulls offer light weight, ease of transport, and unswampable buoyancy.

A boat hull or other marine structure is made by shaping a plastic foam core and covering it with a plastic outer skin glued in place by adhesive, mechanically fastened, or applied in liquid form. Minimal sawcuts to the foam core ease manufacture. Methods for anchoring fittings, masts, pipes and shade canopies are presented. No-sew sails for the boat have corners made of plastic sheet attached using both adhesive and mechanical fastening. Lateral resistance of the hull is provided by telescoping leeboards. A suite of these boats share the same modular masts and sails. Such boat hulls offer light weight, ease of transport, and unswampable buoyancy.

A boat hull with port and starboard side walls that are vertical in cross section whilst the bottom of the hull immediately prior to the commencement of the stern part there-after is horizontal in cross section. Extending throughout the buoyant hulls stern part a longitudinally rectangular flat plate with port and starboard upwardly extending side walls, one each side, are located throughout the length of the vessels stern part. An upwardly directed second rectangular flat plate is arranged fore/aft extends midway between the afore-said side walls to a height in excess of the said side walls. This upstanding plate butts its lowermost edge onto the mid-line of the first said plate. Linking the forward edge of the said longitudinally rectangular plate to the buoyant hull at its aftmost and deepest point are hinges. Thereby allowing an aftwardly upward pivotal movement of the said combined plate, whilst the afore-said upwardly extending fin of the said combination plate to locate within an aftwardly open slot casing that is additionally open upwardly and downwardly, into which the said combination plate moveably but securely fits. Means with which to raise/lower the combination plate are provided. Single or multiple combination plates, as described, operate independently or together.