The purpose of this benthic survey (cruise 0213A) in the southern region Rousay sound, Orkney was to improve knowledge of the occurrence and distribution of species and habitats of recognised conservation importance, particuarly proposed protected features (PPFs) and other priority marine features (PMFs). An underwater video survey were conducted by MSS for MSS on the 8th and 9th February 2013 to collect detailed biological information on the seabed species and habitat features present. Drop-down video drift tows were undertaken at 14 sites within an area of the sound that is at the time of sampling was being proposed as a location for a tidal energy test facility. Analyses on the images, commissioned by SNH, were used to describe the nature of the seabed in terms of the physical structure and the species assemblages. SNH used the vessel FRV Alba na Mara for this survey.