This marine geophysical survey was carried out by British Geological Survey (BGS) and engineers from Hunting Surveys Ltd, Sodera and IOS Barry. The survey took place 27 July to 8 August and 5-18 October 1974 in the Northern North Sea on board the MV Briarthorn. The purpose was to collect data to identify trace reflectors and features observed on deep seismic sections from the project area. Sea floor data were collected using Transit Sonar. Subsurface data were gathered using a suite of seismic instruments (airgun, sparker, pinger and watergun), plus a gravity meter and a magnetometer. These data were recorded as paper records and are archived by BGS. Technical details of the survey are contained in BGS report WB/MG/74/53.