A submersible cage for offshore aquaculture, comprising: a cage (10) for containing aquatic animals； a variable buoyancy float (15)； a flexible element (17) connected at one end to the cage and with the other end arranged such that the weight distribution of the flexible element between the cage and another support (40) can be adjusted by varying the buoyancy of the variable buoyancy float； and a mount structure (40) separate from the cage； wherein the flexible element is connected between the cage and the mount structure； and wherein said flexible element is arranged such that at certain depths of submersion, the flexible element hangs in an arc between the cage and the mount structure. By varying the buoyancy of the variable buoyancy float, the cage can be raised to a floating position (e.g. for maintenance) and submerged to a desired depth. The depth at which the cage is submerged depends on the buoyancy of the variable buoyancy float (15) and can be adjusted freely to suit the conditions. By adjusting the buoyancy to submerge the cage in harsh weather, the cage can be protected from the worst of the conditions. For example, the cage can be submerged to a depth such that it remains well below the troughs of the waves, even in extremely high wave conditions. When the cage is fully submerged it also does not experience high winds and the strengths of storm currents may be weaker at deeper depths. This significantly reduces the stresses that will be experienced by the cage during a storm and thus significantly reduces the engineering requirements and costs.L'invention concerne une cage submersible pour l'aquaculture en mer, comprenant : une cage (10) pour contenir des animaux aquatiques ； un flotteur à flottabilité variable (15) ； un élément souple (17) relié, au niveau d'une première extrémité, à la cage et avec l'autre extrémité agencée de telle sorte que la distribution de poids de l'élément souple entre la cage et un autre support (40) peut être réglée en varian
