This paper details the design, deployment and operation of a power take off system for a 1:4 scale offshore Oscillating Water Column (OWC) Wave Energy Converter (WEC). Ocean energy device prototypes at this scale present a unique set of challenges in that the integration of prime movers and generators typically begins to take place at this particular development stage, which may also represent first deployment at sea. The presence of electrical equipment and rotating machinery in the offshore environment brings its own engineering and operational difficulties. Moreover, such devices are typically not grid connected, necessitating the development of custom power conversion and control equipment. The paper describes the design considerations, details of design, deployment experiences, operational experiences of such a system and concludes with recommendations for future projects in the area. (C) 2010 Elsevier Ltd. All rights reserved.