The purpose of this benthic survey off the west of mainland Orkney was to improve knowledge of the occurrence and distribution of species and habitats of recognised conservation importance, particularly priority marine features (PMFs), and to ground-truth multibeam data. An underwater video and still photograph survey was conducted by MSS for MSS between the 9th and 11th of September 2010 to collect detailed biological information on the seabed species and habitat features present. Drop-down video drift tows were undertaken at 25 sites in the area. The images, analysed under SNH contract by Dr Colin Moore, were used to describe the nature of the seabed in terms of the physical structure and the species assemblages.