A coating film capable of being peeled off in the shape of sheet to facilitate a coating film removal work, and is less likely to peel even after long periods of use on an underwater structure is provided. The coating film comprises an undercoat layer to be bonded to an underwater structure, and an antifouling layer bonded to the undercoat layer, wherein: a 100-gram underwater constant load peeling degree of the coating film is less than 5; a ratio of a tensile breaking strength of the coating film to an adhesive force of the coating film with respect to the underwater structure, as measured after immersing the coating film in pure water at 60° C. for 5 weeks is 1.5 or more; and a 1-mm square cross-cut stretching-caused peeling degree of the antifouling layer with respect to the undercoat layer is 0.05 or less.

A greenhouse for underwater cultivation of terrestrial plant species comprising a dome (2) suitable for being filled with air in an underwater environment, provided with an aperture (21) for lower access and made of a material that is impermeable to water and permeable to light, such dome comprising means for restraining to the sea floor, and means for adjusting the level of water/air in the dome itself which must ensure that plant species cultivated in the greenhouse always reside above such level. Inside such dome a system for the automatic irrigation of the cultivated plants is present comprising a tubular structure (3) on which a plurality of mutually spaced holes (31) is provided, inside which supports are placed for housing and cultivating plant species, irrigation water flowing inside such tubular structure and irrigating such supports in order to achieve a hydroponic culture.

A protective subsea housing for protecting an equipment space enclosed by the housing has an access opening in a wall of the housing for providing access to the equipment space by an unmanned underwater vehicle (UUV). The housing has a closure that is movable by translation, or by rotation relative to an axis transverse to or extending through the wall, to open and close the access opening, and an operating member, such as a rotary coupling, that is positioned outside the equipment space and is engageable and movable by the UUV to move the closure.

A method of installing an object under water at a desired location includes providing the object on a vessel, connecting the object to a submersible frame located below the water surface, wherein the vessel is spatially separated from the submersible frame along the direction of the water surface, releasing the object from the vessel such that the object becomes submerged and carries out a pendulum motion until the object is suspended from the submersible frame, and moving the object to the desired location.

A cofferdam is disclosed that includes an open frame structure having double walls defining a hollow space within each double wall, with each double wall having an open bottom end and a closed top end. Each of the double walls are configured to act as suction piles allowing liquid to be removed from the space within each double wall to thereby induce negative pressure when the cofferdam is installed in a sub-sea configuration. Each of the double walls may include a plurality of partitions respectively defining a plurality of suction piles, the suction piles fluidically coupled by a manifold that may allow liquid to be removed from the suction pile to thereby drive the cofferdam structure into the subsea surface due to the induced negative pressure. A further embodiment cofferdam structure includes an open frame structure and one or more suction piles attached to the open frame structure.

A cofferdam is disclosed that includes an open frame structure having double walls defining a hollow space within each double wall, with each double wall having an open bottom end and a closed top end. Each of the double walls are configured to act as suction piles allowing liquid to be removed from the space within each double wall to thereby induce negative pressure when the cofferdam is installed in a sub-sea configuration. Each of the double walls may include a plurality of partitions respectively defining a plurality of suction piles, the suction piles fluidically coupled by a manifold that may allow liquid to be removed from the suction pile to thereby drive the cofferdam structure into the subsea surface due to the induced negative pressure. A further embodiment cofferdam structure includes an open frame structure and one or more suction piles attached to the open frame structure.

A method of installing an upright elongate hollow subsea foundation that is higher than it is wide, such as a suction pile. The foundation is at least partially embedded in seabed soil. A partition layer is placed within the foundation, for example by injecting a grout, supported by a plug of soil that is surrounded by the foundation. The partition layer is placed on the plug of soil at a level that is spaced from the top of the foundation by at least 20% of the height of the foundation. Above the partition layer, the interior of the foundation may be filled with water and/or a rigid body, such as a solid mass or a hollow liquid-filled tank.

A method for installing a subsea structure at a target installation site in an underwater location is disclosed. The method includes connecting at least one mooring line and at least one leading line to the structure, and towing the structure via the leading line from a deployment position to the target installation site, such that the structure moves both vertically and horizontally between the deployment position and the target installation site. The mooring line is anchored, e.g. to an anchoring device on the seabed, and can incorporate a ballast to apply a sinking force to the structure in proportion to the length of unsupported line. The mooring line and the leading line can together stabilise the structure as it descends to the installation site. The non-vertical installation allows accurate structure placement, e.g. in crowded fields, with less sensitivity to tidal or current forces.

A cooling apparatus for an underwater platform comprising: an evaporator block fabricated from a thermally conductive material and having a first surface that is shaped so as to releasably mate to an exterior surface contour of the underwater platform; a heat pipe having a working fluid sealed therein, wherein the heat pipe has a first end and a second end, and wherein the first end is in thermal communication with the evaporator block; a condenser block in thermal communication with the second end of the heat pipe; and a plurality of spring clamps mounted to the evaporator block and configured to bias the first surface of the evaporator block against the exterior surface of the underwater platform such that heat from the exterior surface of the underwater platform is transferred to the ambient water via the evaporator block, heat pipe, and condenser block.

A method of installing an object under water at a desired location includes providing the object on a vessel, connecting the object to a submersible frame located below the water surface, wherein the vessel is spatially separated from the submersible frame along the direction of the water surface, releasing the object from the vessel such that the object becomes submerged and carries out a pendulum motion until the object is suspended from the submersible frame, and moving the object to the desired location.