The island of Sanday in the Orkney Islands has a low-lying, indented coastline with extensive rocky shores and headlands broken by long, clean sand beaches and muddy inlets. A large section of the island has been proposed as a candidate Special Area of Conservation (cSAC) to protect the common seals, the subtidal reefs and the intertidal sediments. During the summer of 2000, a comprehensive biotope mapping survey of the shores was commissioned by Scottish Natural Heritage (SNH) with the objective of producing broad-scale biotope maps of the intertidal habitats. These would be used to inform SNH's development of conservation objectives and the future management of the site. The survey was carried out in Phase 1 level of detail (Hiscock, 1996; Wyn et al., 2000) using the current (at the time of analysis) national Marine Biotope Classification (Connor et al., 1997a, b). A shoreline length of approximately 73km and an area of 14.7km2 were mapped during this project. The 53 biotopes recorded were combined into 33 biotope groups for presentation on the maps which included an overview of the shore biology as well as maps showing the distribution of biotopes around the island. The coastline was divided into nine broad shore types for the purposes of this report. The survey was divided into 39 sites and within each site the biotopes recorded were listed.