PEN ocean aquaculture engineering is a relatively new area of study. Only in the last 10 to 15 years have engineers started to develop techniques to design and analyze marine aquaculture systems to support the production of a few selected species. Today, a larger variety of fishery products are being considered for grow-out in exposed open ocean environments. Many new types of systems and aquaculture applications are being proposed. Oceanographic conditions, the use of optimized equipment and marketable species will determine the design criteria, which will vary from region to region and country to country. The goal of this Special Issue is to present a sampling of open ocean aquaculture engineering from a global perspective. Articles and Technical Communications were submitted from Canada, the United States, Taiwan, Norway, New Zealand, and Spain. The individual approaches are unique and reflect different sets of engineering considerations. However, the lessons