The rocky coast of West Mainland Orkney (WMO) is characterised by spectacular, sheer cliffs shaped by exposure to extreme wave energy and inhabited by a suite of organisms adapted to this challenging environment. As part of the UK government’s commitment towards developing the renewable energy sector, in March 2010, the Crown Estate announced the leasing of several sites within this area for development of wave energy extraction. Owing to difficulties of access, the biological communities of much of this coastline have never been adequately described. As part of a long-term monitoring programme, we have incorporated boat-based field methodologies to complete the first comprehensive baseline assessment of the littoral community along the entire rocky shoreline of WMO, extending northeast to beyond Costa Head. Within this assessment are: the wave energy converter (WEC) testing site for the European Marine Energy Centre, at Billia Croo; rocky shores within leasing sites potentially impacted by large-scale WEC deployment and subsea cable installation; and areas distant from potential impacts which are serving as control sites. Data collected includes species abundance and several quantitative and semi-quantitative topographical indices which may mediate wave exposure including slope, aspect, openness and complexity. Additional data have been collected for barnacles, patellid limpets and high-energy variant fucoid algae. Comparable sites on the west coast of Lewis have been surveyed by the team and are included in analyses for comparison.