The Firth of Tay and the Eden Estuary are situated on the east coast of Scotland between Carnoustie in the north and St Andrews in the south and the site has been selected as a candidate Special Area of Conservation (cSAC). The qualifying features include estuaries, mudflats and sandflats not covered by seawater at low tide, sandbanks which are slightly covered by seawater all the time and common seals Phoca vitulina. It is also an important site for overwintering wildfowl and waders. In order that a comprehensive management plan can be developed to ensure the sustainable use of resources within the marine cSAC it is essential to obtain an understanding of the geographic distribution and extent of the habitats of interest. A comprehensive biotope mapping survey of the intertidal and subtidal habitats was undertaken in the summer of 2002, by a collaborative research group comprising staff from the University of St Andrews, Heriot-Watt University and SNH. Mapping of the intertidal was accomplished principally through the employment of QuickBird satellite imagery, ground truthed with data collected in intertidal field survey (at a subset of locations samples were collected for sediment infauna and granulometric analysis). Subtidal areas of the site were surveyed by rapid broad scale acoustic techniques, ground truthed with data collected in the field using ROV, epifaunal samples by naturalists dredge and infaunal samples collected by both pipe and Van Veen grab; subsamples retained for granulometric analysis.