The use of GIS tools in marine spatial planning has become widespread. Such tools however often prescribe sterilized zones from a developer’s perspective (e.g. protected areas) and use surrogate indicators of wave and tidal resource with these being used to suggest areas of likely commercial development. The work undertaken in this thesis follows a more dynamic approach which has developed software to model the development appraisal process for wave and tidal projects. This means the most economically feasible sites for development can be located, taking into account factors (such as cable costs) ignored where resolve parameters alone are used in marine spatial planning. Moreover the model developed enables contrasting scenarios for differing harvesting technologies, grid connection points, cable types, port facilities to be examined and for specific improvement plans for such infrastructure to be investigated.