The purpose of this benthic survey off west mainland Orkney was to improve knowledge of the occurrence and distribution of species and habitats of recognised conservation importance, particularly priority marine features (PMFs). A further aim was to assess the implications of renewable energy developments on the features of importance. An underwater video survey was conducted by MSS for MSS on the 2nd March 2012 to collect detailed biological information on the seabed species and habitat features present. Drop-down video drift tows were undertaken at 10 sites. Analyses on the seabed video and still photographic imagery, commissioned by SNH, were used to describe the nature of the seabed in terms of the physical structure and the species assemblages.