The growth of the marine aquaculture sector, and increasing interest and demand in using less protected offshore waters has brought about a range of opportunities and challenges. A number of production systems are already being developed, some of which are now reaching the technological and operational point where they may be considered to be truly offshore systems. However, many other systems and installations have been found to be inadequate for intended objectives, and in circumstances where capital and operating costs must be kept within strict boundaries, excessive damage and loss may create significant disincentives to development. This paper outlines the technical and operational criteria which must be considered for effective offshore mariculture, emphasizing the need to understand the full systems context to ensure that production can be achieved in a secure and cost-effective manner. Implications for development planning are also discussed.