The survey was led by the Joint Nature Conservation Committee, in collaboration with the Marine Institute, the British Geological Survey and the University of Plymouth. Defra Natural Environment Group Science Division (CRO 361) made a significant contribution to this work. This work contributed to the MESH project (www.searchmesh.net). The MESH Project ran between 2004 and 2008 and was made up of a consortium of twelve partners from five European countries led by the UK’s Joint Nature Conservation Committee (JNCC), with financial support from the EC’s INTERREG IIIB NWE Programme. The MESH partnership drew together scientific and technical habitat-mapping skills, expertise in data collation and its management, and proven practical experience in the use of seabed-habitat maps for environmental management within national regulatory frameworks. The aims of the R/V Celtic Explorer cruise (CE0705) on 4th-18th June 2007 were to acquire high resolution multibeam, sub-bottom profiler and camera data in the SW Approaches area, located approximately 320km southwest of Land's End. The cruise not only mapped the variable morphology of the SW Approaches area, but also investigated the biological communities within the canyon system for the assessment of potential Special Areas of Conservation (SAC) under the EC Habitats and Birds Directive (Annex I) (Johnston et al. 2002). The cruise also tested the application of the survey standards and protocols developed under the MESH project. The cruise was the first thorough test for the recently completed MESH Guidance Framework, providing a 'proof of concept' from planning to completion. The backscatter and geophysics data are archived and available for download at the British Geological Survey (BGS) MEDIN Data Archive Centre (DAC) for Geology and Geophysics. Biological and bathymetry data are archived at DASSH and UKHO respectively. Technical details of the survey are contained in BGS Commissioned Report CR/07/123N (http://nora.nerc.ac.uk/id/eprint/507379/). Final Report (http://nora.nerc.ac.uk/id/eprint/507378/). GeoIndex Offshore - https://mapapps2.bgs.ac.uk/geoindex_offshore/home.html?cruise=2007/6_MESH&;.