This sampling and geophysical survey has been carried out by British Geological Survey (BGS) for BGS, the survey took place in September to November 1968 in the Sea of the Hebrides and the Minch on board the RRS John Murray. These purpose was to collect data to investigate the sub-surface geological structure and sea-bed geology additional geophysical observations were planned for the return passage to Plymouth including a detailed survey of a small area in the southern Irish Sea (see 1968/Passage survey for details). Sea floor data were collected using echo sounder. Sub-bottom profiling data were collected using sparker and sidescan sonar. Gravity meter and magnetometer data were collected. Sample data were collected using shipek grab, sediment dredge,rock dredge and scuba diving. These data are archived by BGS. Technical details of the survey are contained in BGS report WB/MG/68/28.