An offshore aquaculture system 100 comprises a semisubmersible platform 110 having storage and maintenance facilities 115 for supporting aquaculture with an attached framework 120, to which net covered rigid aquaculture cages 130 are attached and used for aquaculture. The cages are movably connected and controllably positioned according to sea conditions. The cages may be sunk or raised to protect the aquaculture products, and all maintenance and feeding is carried out by crew onboard the platform 110. The cages have a vertical dimension larger than their horizontal dimension and are vertically movable with respect to the platform by means of a motor (141) controlled by a control unit (150) according to sea conditions as measured and anticipated by measurements from meteorological sensors.
