The sampling cruise took place in August 1992 in the region of the Hebridean Terrace west of the Outer Hebrides in the vicinity of the Barra Fan aboard the RRS Charles Darwin. The purpose was to locate and sample marine gas and il seeps on the seafloor. The cruise was undertaken jointly by the British Geological Survey, Marine Biological Association, Plymouth and Dunstaffnage Marine Laboratory in order to integrate the geology with the biology and chemistry of these seeps. Seabed samples were collected using gravity corer; box corer, Agassiz trawl and epibenthic sledge. CTD data were also collected. Sea floor data were collected using Echo sounder. Subsurface seismic data were gathered using Pinger. Technical Details of the survey are contained in BGS cruise report WB/92/25 or WB/92/212.