Open ocean aquaculture is a rapidly growing industry with the potential to satisfy the global seafood demand in the environment of declining wild fish harvesting. However, technologies developed for inshore aquaculture are not easily transferrable to the exposed fish farm locations. In particular, the structural integrity of fish cage/mooring systems, and the high cost of the maintenance (cleaning of the biofouled netting) are two major concerns in the engineering for open ocean aquaculture. This paper deals with introduction of copper alloy nets in open ocean aquaculture as a new technology to reduce biofouling, improve cage volume stability, its structural strength, and to provide additional protection from predators. Copper alloys have natural resistance to corrosion and biofouling combined with high strength and stiffness. However, these materials have higher density, different hydrodynamic properties and structural characteristics when compared to traditionally used nylon nets. The paper presents novel design and fabrication procedures needed for engineering of the offshore fish farms utilizing copper alloy netting. These procedures are illustrated on a commercial size gravity-type offshore fish cage, which was designed and successfully deployed in the Pacific Ocean near Isla Italia (Patagonia, Chile).