Fish netpen

A netpen for breeding, storage, or transport of fish, the netpen comprising:

• a flexible framework of stays mainly composed of polyethylene materials containing fibers;
• a substantially horizontal center pole extending through the netpen and having sufficient stiffness to serve as an attachment and supporting structure for the netpen, and wherein the center pole further serves as a buoyancy adjusting element for the structure through the adjustment of an amount of water and an amount of air in the center pole;
• and
• a substantially horseshoe-shaped truss with a working deck attached at each end of the center pole, so that the truss with the working deck may be used as a platform or haunt to support personnel performing work operations on the netpen when the installation is in a semi-submerged or substantially semi-submerged floating position, a docking unit extending from the substantially horseshoe-shaped truss, wherein the docking unit includes a plurality of truss members, a plurality of fenders, and at least one element for adjusting the buoyancy through adjustment of the amount of water in the at least one element, so that the entire horseshoe including the docking unit is arranged for being lowered to a position underneath the netpen, wherein:
• the netpen is lowerable into water when needed,
• the netpen is moveable between a semi-submerged state for the performance of one or more work operations and a fully submerged state,
• the netpen has the shape of a substantially dual curved body and is rotatable about a substantially horizontal axis, and
• the substantially horizontal axis remains substantially horizontal in both the semi-submerged state and in the fully-submerged state.