<p>Resource assessment is an essential step in the reconnaissance to feasibility study stages of marine renewable energy development. However, minimization of uncertainties associated with the estimation requires that data be provided at a sufficiently high resolution and duration long enough to include effects of climate variation. This paper describes a recently completed dataset of wave power, ocean and tidal current power, and ocean temperature power. The estimate is based on a 21-year hindcast of waves at a 1 km resolution along the coast of Japan and a 10-year hindcast of ocean and tidal current at a 3 km resolution around Japan. Power is estimated as a long-time mean at various scales and uncertainties are quantified as well.</p>