This paper presents the status of marine applications for renewable energy as of 2008 from a U.S. perspective. The technologies examined include wave, tidal, and ocean current energy extraction devices that are currently being demonstrated in at least one ocean project. The paper also examines the resources for each of these technologies, the limitations to the current assessments, and the research and development needs of the marine renewable energy industry based on the author’s experience and opinions. It provides an overview of the National Renewable Energy Laboratory and its capability to meet some of the industry’s R&D needs as a technology integrator and a third party evaluator. The paper concludes that marine energy resources are globally significant and should be developed as part of the diverse clean energy portfolio that will be necessary to reach expected future carbon reduction targets. No single energy source will be able to achieve these reductions independently so many sources must be simultaneously developed.