The survey area for the study is the St. Kilda cSAC boundary. The candidate site was put forward for designation under the EU Habitats Directive. The coast and inshore waters of St. Kilda comprise some of the most rugged and wave exposed rocky reefs and some of the finest examples of sea caves to be found in the UK. The western location of the archipelago is such that it is more strongly influenced by the North Atlantic Drift than inshore areas. In order to effectively manage marine SAC's it is considered essential to have suitable information on the distribution and quality of the habitat and species that occur within the site boundaries. Such information is necessary to allow conservation interests to be matched to possible management measures. This information can be used to assist in the development of SNH's statutory advice regarding the St. Kilda cSAC, and will be of great assistance in developing a management scheme for the site. It was, therefore, proposed that a baseline mapping survey of the habitats within the St. Kilda cSAC was carried out which included sublittoral and littoral habitats.