Apparatus and associated methods relate to using an additive (material deposition) process to incrementally form a closed-cell lattice structure formed as a unitary body in the shape of a marine hull cavity, the unit cells of the closed-cell lattice structure are substantially hollow. In an illustrative example, a method may include (a) forming a closed-cell lattice structure through additive manufacture, the hull cavity material may be bonded to an upper manufactured liner and a lower manufactured liner through lamination or mechanical connection. Unit cells of the closed-cell lattice structure may include hollow voids filled with gases. Providing the additive manufactured closed-cell lattice structure with a unitary body and hollow voids to trap gases may further advantageously promote the buoyancy and reduce the degeneration of a marine hull.

The invention relates to a method for constructing and/or manufacturing a water sports device (2) which has a modular structure comprising a floating body (4). The modules can be connected together via interfaces and are connected during operation. In particular, the invention relates to a method for constructing and/or manufacturing a foilboard or driver propulsion vehicle, wherein a server device is provided, and a program-controlled input interface is provided for user-defined inputs on a terminal (5), in particular a mobile terminal, which is arranged at a distance from the server device in particular. The modules are imaged in a computer program of the server device and/or of the terminal (5), and at least one outer contour of the floating body (4) of the water sports device (2) can be, in particular, freely defined by the user. On the basis of the outer contour of the floating body (4) defined in the program, automated manufacturing information is produced, and the floating body (4) manufactured according to the production information can be combined with another module, in particular multiple other modules, to produce the water sports device (2). The invention also

In one example, a method includes positioning, within a mold, a device with a movable element that defines a portion of a volume, and the volume is contained within the mold, as part of a molding process, at least partly defining a molded watercraft by introducing plastic into the mold, disposing the plastic about the movable element, and with the movable element, excluding the plastic from the portion of the volume that is defined by the movable element so as to define a recess and an undercut that are integral with the watercraft and extend lengthwise with respect to a centerline of the watercraft, and the recess and undercut are integral, and communicate, with each other.

A molded boat with a seat drain. The boat includes a molded hull having been molded using a first material to cause the boat to have a front portion and a rear portion. The boat is molded with a bench, having been molded together with the hull using the first material. The bench includes a drain hole formed through, an otherwise solid face of the bench allowing water to flow from the front portion of the boat to the rear portion of the boat, wherein the drain hole formed through the bench is formed by using a tube molded into, and under the bench, the tube comprising a material having a higher melting point than the first material.

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.

An article of manufacture including molded-in notches in the peripheral edge of long, uninterrupted molded-in compartments in a rotational molded boat hull for permitting the flush fitting of certain independent structural members in said notches to provide both structural support and drainage of water away from seams between adjacent deck panels and hatches secured over the compartments without resorting to elaborate pre-fabricated decks. The article of manufacture includes a body, wherein the body is a plastic molded boat hull comprised of numerous molded-in cavities and molded-in features to create an interior layout that is comparable to a conventional boat built of aluminum or fiber reinforced plastic.

An article of manufacture involving a system of molded-in cavities and post-molded cover plates that solve a multitude of problems in applying rotational molding to the construction of plastic-hulled power boats. The article of manufacture includes a body, wherein the body is a plastic molded boat hull comprised of numerous molded-in cavities and molded-in features to create an interior layout that is comparable to a conventional boat built of aluminum or fiber reinforced plastic.

In one example, a method includes positioning, within a mold, a device with a movable element that defines a portion of a volume, and the volume is contained within the mold, as part of a molding process, at least partly defining a molded watercraft by introducing plastic into the mold, disposing the plastic about the movable element, and with the movable element, excluding the plastic from the portion of the volume that is defined by the movable element so as to define a recess and an undercut that are integral with the watercraft and extend lengthwise with respect to a centerline of the watercraft, and the recess and undercut are integral, and communicate, with each other.

A hull for a personal watercraft includes a compression-molded hull body. A main portion of the hull body includes a thermoplastic material embedded with non-directional chopped glass fibers. The main portion extends along an entirety of the length and of the width of the hull body. Port and starboard portions of the hull body include the thermoplastic material embedded with directional glass fibers. The directional glass fibers include longitudinally-oriented glass fibers. A majority of the longitudinally-oriented glass fibers have a length at least ten times greater than a mean length of the chopped glass fibers. The port and starboard portions extend vertically from proximate an upper edge of the hull towards a keel, and longitudinally along at least 50% of the length of the hull body.

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.