This British Geological Survey (BGS) marine geophysical survey took place in May and June 1985 in the NW continental margin on board the MV Gorsethorn. The purpose was to collect data as part of the UK continental shelf survey programme. The main objective was to survey a series of deep-tow boomer/sparker profiles down the West Hebridean and West Shetland slopes. Sea floor data were collected using echosounder; deep-tow sidescan sonar and transit sonar. Sub-bottom seismic profiling data were collected using pinger; deep-tow boomer and deep-tow sparker. Gravity data were recorded. These records are archived by BGS. Details of the survey data processing are contained in BGS report WB/89/12R.