Power generation from waves and tidal currents is a nascent industry with the potential to make globally significant contributions to renewable energy portfolios. Further development and deployment of the related, immature technologies present opportunities to benignly tap large quantities of renewable energy; however, such development and deployment also present numerous engineering, economic, ecological, and sociological challenges. A complex research, development, demonstration, and deployment environment must be skillfully navigated if wave and tidal power are to make significant contributions to national energy portfolios during the next several decades.