Every year since its inception in 2001 the Ocean Energy Systems Implementing Agreement (OES) Executive Committee (ExCo) has published an Annual Report, which details its activities over the previous year and includes on ocean energy activities supplied by each ExCo member country. The 2008 Annual Report started a tradition of including a series of invited articles, on a specific theme, by acknowledged industry experts. These invited articles examine current issues in the development of ocean energy technologies and provide insights into changing circumstances within ocean energy, e.g., forecasting cost of energy for different technologies.