The survey of the marine environment around Flamborough Head was undertaken as part of the BioMar Project which is funded by the European Community through the LIFE Programme. Conflicting data were available to determine the offshore extent of these chalk reefs: estimates varied between 1 and 15 km offshore. To implement effective management of the marine benthic resource, English Nature required data on the geographic extent of the biotopes around Flamborough Head and requested the BioMar project at the University of Newcastle to conduct a biotope mapping survey. This was done using acoustic techniques validated by biological sampling, with the data stored and analysed using geographic information systems (GIS).