A pontoon boat includes port and starboard pontoons and cross members connecting the pontoons. A shock absorber may be installed at each point of connection of the pontoons to the cross members. A cross member may be embodied as a double-webbed beam having first and second parallel flanges and first and second webs disposed between and connected to the flanges. Each pontoon may include a two-stage lifting strake having a first surface and a second surface inclined from the first surface.

A pontoon boat includes port and starboard pontoons and cross members connecting the pontoons. A shock absorber may be installed at each point of connection of the pontoons to the cross members. A cross member may be embodied as a double-webbed beam having first and second parallel flanges and first and second webs disposed between and connected to the flanges. Each pontoon may include a two-stage lifting strake having a first surface and a second surface inclined from the first surface.

A watercraft includes a pair of inflatable pontoons. Releasably affixed atop each of the pontoons and aligned therewith are inner and outer lengthwise frame members. Forward and aft beamwise frame members are affixed to the inner and outer lengthwise frame members. Primary arch members are affixed to the forward and aft beamwise frame members. A main fabric panel is stretched between the pair of primary arch frame members, the forward beamwise frame member, and the aft beamwise frame member. A motor mount is affixed centrally to the aft beamwise frame member, the motor mount being configured to removably support a motor assembly. Aft panel side members are rotatably-lockably affixed to the aft beamwise frame member and joined by an aft panel top member. An aft fabric panel is stretched between the aft panel side members, the aft beamwise frame member, and the aft panel top member.

A watercraft includes a pair of inflatable pontoons. Releasably affixed atop each of the pontoons and aligned therewith are inner and outer lengthwise frame members. Forward and aft beamwise frame members are affixed to the inner and outer lengthwise frame members. Primary arch members are affixed to the forward and aft beamwise frame members. A main fabric panel is stretched between the pair of primary arch frame members, the forward beamwise frame member, and the aft beamwise frame member. A motor mount is affixed centrally to the aft beamwise frame member, the motor mount being configured to removably support a motor assembly. Aft panel side members are rotatably-lockably affixed to the aft beamwise frame member and joined by an aft panel top member. An aft fabric panel is stretched between the aft panel side members, the aft beamwise frame member, and the aft panel top member.

A truss system may include a plurality of beams. Each beam of the plurality of beams may have various cross-sectional sizes in a same plane. Additionally, the plurality of beams may have a geometric arrangement such that a structural weight at required strength level may be reduced to achieve optimal design.

A truss system may include a plurality of beams. Each beam of the plurality of beams may have various cross-sectional sizes in a same plane. Additionally, the plurality of beams may have a geometric arrangement such that a structural weight at required strength level may be reduced to achieve optimal design.

Disclosed is a method for stiffening plates for ship walls. At least one elongate profile member of laminated composite material and having a transverse cross-section of a predetermined shape over the length thereof is pre-manufactured, the profile member being rigid. Then, a panel including laminated composite materials at least on the surface of at least one of the two main surfaces thereof is used, and the at least one pre-manufactured profile member is assembled and attached together onto one of the main surfaces of the panel. The main surface of the panel receives the profile member including laminated composite material. The profile member has a transverse cross-section with three continuous portions: two flanges having substantially straight cross-sections and interconnected by a web. The flanges and the web in transverse cross-section are supported by separate planes, the plane of the web intersecting the two planes, supporting the flanges, at 90.

Disclosed is a method for stiffening plates for ship walls. At least one elongate profile member of laminated composite material and having a transverse cross-section of a predetermined shape over the length thereof is pre-manufactured, the profile member being rigid. Then, a panel including laminated composite materials at least on the surface of at least one of the two main surfaces thereof is used, and the at least one pre-manufactured profile member is assembled and attached together onto one of the main surfaces of the panel. The main surface of the panel receives the profile member including laminated composite material. The profile member has a transverse cross-section with three continuous portions: two flanges having substantially straight cross-sections and interconnected by a web. The flanges and the web in transverse cross-section are supported by separate planes, the plane of the web intersecting the two planes, supporting the flanges, at 90.

A marine hull including a hull plate manufactured from metal, a set of longitudinal reinforcements and a set of transverse reinforcements, at least one longitudinal reinforcement of the set of longitudinal reinforcements being arranged between the hull plate and at least one transverse reinforcement of the set of transverse reinforcements, and being connected to an inside of the hull plate. The marine hull is characterized in that the hull plate has a thickness that is less than 10 mm, and that the at least one longitudinal reinforcement is manufactured from the same metal as the hull plate and comprises at least one resilient segment arranged to spring in the direction transverse to the thickness of the hull plate, and that the resilient segment is arranged to bottom upon a compression that is more than 10 mm and less than 50 mm.