An underwater structure includes a half cylinder with ribs arranged on an interior surface. The half cylinder and the ribs are a semi-monocoque structure including a fiber reinforced thermoplastic composite.

There is provided an assembleable aquaboard made of fiber-reinforced plastic (FRP), including: a first plate having a first T-shaped slot on the top surface and a second T-shaped slot on the right side surface, a second plate having a third T-shaped slot on the top surface and a fourth T-shaped slot on the right side surface; a third plate having a fifth T-shaped slot on the top surface, a sixth T-shaped slot on the right side surface; a fourth plate having a seventh T-shaped slot on the top surface and an eighth T-shaped slot on the left side surface; a first T-shaped connector to connect the first and the third plates; a second T-shaped to connect the second and the fourth plates; and a first I-beam connector to connect the first plate, the second, the third plate and the fourth plate to form the assembleable aquaboard.

A unique watercraft that includes a plurality of flotation elements which are aligned longitudinally and fit together end to end, comprising the watercraft hull. Unlike other watercraft, it does not rely upon a low center of gravity for stability. A front flotation element pivots about an axis and this pivotal motion is used for both steering and for maintaining balance. The effective profile of the hull changes dynamically as the front flotation element is turned. These hull changes allow the operator to balance and make agile maneuvers. Equilibrium can be easily maintained in this manner when the watercraft is moving forward and when it is otherwise stationary in water. In a preferred embodiment, the watercraft is ridden like a bicycle. Balance is actively maintained by a rider who steers right and left to adjust transverse weight distribution. The riding experience feels similar to operating a conventional bicycle on land.

The present disclosure relates to drifters that float and take measurements at, or very near, a surface of a body of water. The drifters may have a design that reduces wind force effects but does not diminish Stokes drift force effects. The drifters may have two opposing exterior surfaces with antennas and sensors on each of the opposing surfaces so that the drifters may always utilize at least some of the antennas and sensors, regardless of the drifter's orientation in the water.

In a method for producing a hull wall of a fiber composite sandwich component, shaped bodies of extruded polystyrene hard foam are enveloped with an envelope of fiber composite material with fibers oriented at least bidirectionally. The enveloped shaped bodies have a shape for forming a hull wall and are placed next to each other in a vacuum injection structure on a lower cover layer of fiber composite material. An upper cover layer of fiber composite material is placed on top of the enveloped shaped bodies and the vacuum injection structure is sealed. Matrix material is introduced and distributed in the vacuum injection structure until the fiber composite material of the envelopes and of the upper and lower cover layers is impregnated completely with the matrix material. The matrix material is cured and the fiber composite sandwich component of the hull wall is removed from the vacuum injection structure.

A unique watercraft that includes a plurality of flotation elements which are aligned longitudinally and fit together end to end, comprising the watercraft hull. Unlike other watercraft, it does not rely upon a low center of gravity for stability. A front flotation element pivots about an axis and this pivotal motion is used for both steering and for maintaining balance. The effective profile of the hull changes dynamically as the front flotation element is turned. These hull changes allow the operator to balance and make agile maneuvers. Equilibrium can be easily maintained in this manner when the watercraft is moving forward and when it is otherwise stationary in water. In a preferred embodiment, the watercraft is ridden like a bicycle. Balance is actively maintained by a rider who steers right and left to adjust transverse weight distribution. The riding experience feels similar to operating a conventional bicycle on land.

The invention relates to a surfboard having a hull (22) and a jet drive (2) arranged in the hull (22) and a battery arranged in the hull (22) for the jet drive (2), wherein the jet drive (2) is mounted on a carrier (17) and the carrier (17) can be releasably fastened to the hull (22) by fastening means and can be removed from the hull (22) together with the jet drive (2) after the release of the fastening means.

There is provided an assembleable boat made of fiber-reinforced plastic (FRP) including a bottom wall assembly; a left side wall assembly; a right side wall assembly; and a front wall assembly. the bottom wall assembly, the back wall assembly, the left side wall assembly, the right wall assembly, and the front wall assembly are mechanically connected to form the assembleable boat; and each of the bottom wall assembly, the left side wall assembly, the right wall assembly, and the front wall assembly is made of FRP.

A composite floating dock system comprised of one or more dock float components, with each dock float component having a dock frame and one or more floats attached thereto, with each of the dock float components constructed of fiberglass reinforced plastic into a single monolithic unit, and being ballasted with encased concrete.

A boat with a foam material filled keel structure comprising: a buoyant body, which is a U-shaped tube; a bottom plate, set on the bottom of the buoyant body; a tail plate, set at the rear of the buoyant body and the bottom plate; and a keel structure, set on the bottom of the bottom plate; wherein the keel structure is downward depressed, hence a convex part on the bottom and a groove on the top are formed; wherein in the groove of the keel structure is filled with foam material, Thereby it is achieved that water seepage in the keel structure is avoided.