A buoyancy system is for a fish pen. The fish pen has an enclosure for keeping fish confined in the fish pen, the enclosure being secured to an inner flexible buoyancy body floating on a water surface. The buoyancy system has an outer buoyancy body on the outside of the inner buoyancy body. The inner buoyancy body is attached to the outer buoyancy body with a mooring so that the outer buoyancy body and the inner buoyancy body move independently of each other relative to waves.

A buoyancy system is for a fish pen. The fish pen has an enclosure for keeping fish confined in the fish pen, the enclosure being secured to an inner flexible buoyancy body floating on a water surface. The buoyancy system has an outer buoyancy body on the outside of the inner buoyancy body. The inner buoyancy body is attached to the outer buoyancy body with a mooring so that the outer buoyancy body and the inner buoyancy body move independently of each other relative to waves.

An aquatic system configured for suspending a structure (2; 9; 20; 21) in a body of water (W), comprising at least two buoyancy control arrangements (15) configured for connection to the structure (2; 9; 20; 21) and to a seabed (B) below the body of water (W). The structure (2; 9; 20; 21) is moored to the seabed (B) via the at least two buoyancy control arrangements (15). Each buoyancy control arrangement (15) comprising a first buoyancy device (4) and a second buoyancy device (3), the buoyancy of each of the first buoyancy devices (4) and each of the second buoyancy devices (3) is independently controllable in order to adjust the vertical and horizontal position of the structure (2; 9; 20; 21) and vertical and horizontal restoring capacity of the aquatic system in the body of water (W).

An aquatic system configured for suspending a structure (2; 9; 20; 21) in a body of water (W), comprising at least two buoyancy control arrangements (15) configured for connection to the structure (2; 9; 20; 21) and to a seabed (B) below the body of water (W). The structure (2; 9; 20; 21) is moored to the seabed (B) via the at least two buoyancy control arrangements (15). Each buoyancy control arrangement (15) comprising a first buoyancy device (4) and a second buoyancy device (3), the buoyancy of each of the first buoyancy devices (4) and each of the second buoyancy devices (3) is independently controllable in order to adjust the vertical and horizontal position of the structure (2; 9; 20; 21) and vertical and horizontal restoring capacity of the aquatic system in the body of water (W).

A segment for a modular floatation collar comprises a frame having a recessed compartment and a removable decking covering the recessed compartment. The frame is mounted on a floatation unit. There are a plurality of rigging hardpoints and a plurality of installation hardpoints disposed along the frame. A universal connection at each end of the frame allows the segment to be connected to an adjacent segment either linearly along a common axis or orthogonally at a right angle. The floatation unit extends between adjacent segments in the floatation collar.

A segment for a modular floatation collar comprises a frame having a recessed compartment and a removable decking covering the recessed compartment. The frame is mounted on a floatation unit. There are a plurality of rigging hardpoints and a plurality of installation hardpoints disposed along the frame. A universal connection at each end of the frame allows the segment to be connected to an adjacent segment either linearly along a common axis or orthogonally at a right angle. The floatation unit extends between adjacent segments in the floatation collar.

An offshore wind-solar-aquaculture integrated floater is provided, including vertical-axis wind turbine systems, solar photovoltaic panels, and a cube aquaculture cage. Four vertical-axis wind turbine systems are respectively rigidly connected to four corners of the cage; solar photovoltaic panels and a living and working quarter are located on cage deck; and side frames of the cage are equipped with tensile nets, the bottom frame of cage is equipped with a bottom net, and columns of the cage are equipped with lifting rails. This floater has good stability, sea-keeping performance and high strength. Utilizations of offshore wind and solar energy above the cage are high and they complement each other in power generation. This disclosure manages to exploit ocean resources to an unprecedentedly large extent, while resolving the issue of combing power generation with marine aquaculture in moderate and deep seas.

An offshore wind-solar-aquaculture integrated floater is provided, including vertical-axis wind turbine systems, solar photovoltaic panels, and a cube aquaculture cage. Four vertical-axis wind turbine systems are respectively rigidly connected to four corners of the cage; solar photovoltaic panels and a living and working quarter are located on cage deck; and side frames of the cage are equipped with tensile nets, the bottom frame of cage is equipped with a bottom net, and columns of the cage are equipped with lifting rails. This floater has good stability, sea-keeping performance and high strength. Utilizations of offshore wind and solar energy above the cage are high and they complement each other in power generation. This disclosure manages to exploit ocean resources to an unprecedentedly large extent, while resolving the issue of combing power generation with marine aquaculture in moderate and deep seas.

A modular agriculture system for use underwater. The system comprises a plurality of node elements (101) each including an agricultural unit and a plurality of connection elements (201) for inter-connecting at least some of said nodes to form a mesh-like structure with nodes at the mesh junctions. A significant portion of said connection elements (201) are of low cross section such that when in use and placed underwater they present a low resistance to the action of waves and currents. A plurality of tensioning elements are connected to the mesh-like structure to place the connection elements (201) in tension.

A buoyancy system is for a fish pen. The fish pen has an enclosure for keeping fish confined in the fish pen, the enclosure being secured to an inner flexible buoyancy body floating on a water surface. The buoyancy system has an outer buoyancy body on the outside of the inner buoyancy body. The inner buoyancy body is attached to the outer buoyancy body with a mooring so that the outer buoyancy body and the inner buoyancy body move independently of each other relative to waves.