Described herein are watercraft comprising a hull comprising a first hull assembly, and a second hull assembly opposite the first hull assembly and parallel to the first hull assembly; and a frame configured to couple the first hull assembly to the second hull assembly. In sonic embodiments, the first hull assembly comprises a first quarter hull coupled to a second quarter hull, and the second hull assembly comprises a third quarter hull coupled to a fourth quarter hull. In some embodiments, the first and third quarter hulls are substantially reflectively duplicative of the second and fourth quarter hulls. In some embodiments, the first hull assembly is substantially reflectively symmetrical to the second hull assembly. Various embodiments may further include a roof comprising one or more energy harvesting arrays thereon. The roof may be movable, in various embodiments, between a closed configuration and an open configuration.

A flexible floating reservoir for storing liquids denser than the environmental body of water, such as sea salt brine, is provided. The flexible floating reservoir is adaptable to environmental body waves, such as sea waves. A method for operating the flexible floating reservoir and an underwater energy storage system that uses the flexible floating reservoir are also provided.

An offshore LNG processing plant includes a first module including a personnel accommodation facility on a first vessel, a second module including a gas treatment facility on a second vessel, and a third module including a gas liquefaction facility on a third vessel. Each of the first, second, and third modules are assembled on the corresponding vessels, and then transported to an offshore location in a body of water, such as a river, a lake, or a sea. At the offshore location, each vessel deploys legs to the bed of the body of water to raise a hull of each vessel out of the water. The first module is then coupled to the second module, and the second module is coupled to the third module. A fourth module on a fourth vessel is coupled to the third module to provide LNG storage.

A system provides impressed current cathodic protection (ICCP) of a marine structure (50) and powers a load in a load arrangement (100) arranged on the marine structure (50) and in contact with the water (10). The power source provides a supply current to generate an electrical potential of the marine structure. The load arrangement (100) has an electrode arranged (130) to extend from the load arrangement into the water for transferring the supply current via the water. The load (20) is coupled between the electrode (130) and a power node (120). The power source is connected to the marine structure and to the power node. The load arrangement is arranged to use the supply current to provide power to the load. Thereto the supply voltage may have an AC component at a high frequency. The load may be an UV-C LED for emitting anti-fouling light.

A method for constructing a wind turbine concrete floater including a central connector from which radial arms extend, the central connector carrying a central stability tower, and each arm carrying an outer stability tower. The method includes prefabricating the arms, central connector and at least parts of the stability towers, pre-assembling the central connector with one arm to form a primary pre-assembly, mounting temporary flotation devices onto the arms to provide additional buoyancy to them, floating the primary preassembly and floating the other arms of the floater, and assembling offshore said primary preassembly with said other arms.

An offshore floating island includes a supporting structure and an island main body. The bottom of the supporting structure is fixed at the seabed, and the island main body includes one or two or more compartment bodies; the upper part of the supporting structure is provided with a carrying part; the bottom of each compartment body is provided with a mounting part; the compartment body is of a cavity structure, and a filler is injected to the compartment body till the compartment body sinks to cause the mounting part to be in lock type clamping with the carrying part. The island main body is of a compartment-sinking type structure; the filler is poured into the compartment bodies to cause the compartment bodies to sink; the mounting parts and the carrying part cooperate to realize detachable connection between the supporting structure and the compartment bodies.

An offshore floating island includes a supporting structure and an island main body. The bottom of the supporting structure is fixed at the seabed, and the island main body includes one or two or more compartment bodies; the upper part of the supporting structure is provided with a carrying part; the bottom of each compartment body is provided with a mounting part; the compartment body is of a cavity structure, and a filler is injected to the compartment body till the compartment body sinks to cause the mounting part to be in lock type clamping with the carrying part. The island main body is of a compartment-sinking type structure; the filler is poured into the compartment bodies to cause the compartment bodies to sink; the mounting parts and the carrying part cooperate to realize detachable connection between the supporting structure and the compartment bodies.

A device for extracting energy from flowing fluid is provided. First and second buoyant lateral side members are provided. A fluid turbine is disposed between and below the lateral side members. At least one support extends from each side member to the turbine. At least one adjustable length support connects to the first and second side members, the at least one adjustable length support being adjustable between a minimum length and a maximum length. When a length of the adjustable length support adjusts toward the minimum length the first and second side members move closer together to thereby lower the turbine relative to the lateral side members. When the length of the at least one adjustable length support adjusts toward the maximum length the first and second side members move away from each other to thereby raise the turbine relative to the lateral side members.

A floating dam or island is provided by pre-fabricating modular hollow bodies. A first group of modular bodies is laid floating on a water surface, positioning the modular bodies in mutual side-to-side arrangement so as to delimit therebetween intermediate gaps within which the reinforcing rods are protruding. A first concrete casting is performed into the gaps and over the modular bodies so as to render them mutually joined. A second group of modular bodies is then laid over the first group and a second concrete casting is performed in order to join the first and second group together. Additional groups of modular bodies are laid and further concrete castings are performed up to obtaining a monolithic block having a desired floating dam or island configuration.

An unmanned, autonomous, self-sustaining and self-repairable floating platform which is positioned at a fixed location within the sea, capable of constantly monitoring, without having to be removed, a specific maritime zone including a sea surface area and the aerial and underwater space pertaining to this sea surface area, the platform comprising telecommunication means adapted to exchange surveillance related information with a Command, Communication and Control center. The platform comprises a deck maintained well above sea surface through a connecting member with an underlying, fully or partially submerged, system of floaters and is equipped with a variety of sensors and surveillance systems such as radar, Li-dar, sonar, electromagnetic, unmanned vehicles (UAVs, UUVs and USVs), active and passive self-protection systems as well as research and rescue equipment. A mast having a substantial height (usually 40-50 m) and equipped with appropriate surveillance devices is mounted and ex-tends vertically upwardly the deck.