An open ocean aquaculture net pen syste1n was developed for offshore deployment south of the Isles of Shoals, New Hampshire, USA in 55 meters of water. Two cages were specified for the growout of summer flounder as part of an interdisciplinary effort at the University of New Hampshire involving engineers, biologists, economists, and commercial fishermen. This effort included the design of mooring system suitable for the offshore environment. Assembly and deployment of these cages and associated moorings occurred in the summer of 1999. An overview of the procedures and techniques used during these efforts are presented here.