This Web service provides layers which show data relating to offshore survey activities undertaken by the British Geological Survey (BGS) and its predecessors. The layers are polygon, line and point layers which indicate the spatial areas of survey activities. The survey overview layer shows the location and basic information for coastal and marine surveys. It includes information about the survey, including the types of equipment deployed during the survey. For some surveys, a zip file of additional data can be downloaded using the URL link provided where available. The geophysical surveys layers show survey lines and shot points along those lines, where applicable. Geophysical surveys include shallow seismic reflection (e.g. airgun, boomer, pinger, sparker and water gun) and sonar (e.g. echo sounder, sidescan sonar and transit sonar). There may be several types of equipment deployed on a single survey line. Survey lines are uniquely named with a survey and line identifier (name or number). For example, 1985/6#16 is line 16 of survey 1985/6. The lines layer includes seismic reflection (sub seabed imaging which provides information about structures below the seabed) and sonar (seabed imaging which provides information about the roughness of the seabed or simple bathymetric data). Links to scanned images of geophysical records are provided (where available) for openly available survey lines where terms of use are known. The backscatter layer shows the location and basic information for bathymetric surveys containing backscatter data. A zip file of the backscatter image files for the survey can be downloaded using the URL link provided. Note that there can be more than one polygon per survey and these will link to the same zip file for the entire survey. The majority of the data were collected and processed for the Maritime and Coastguard Agency (MCA) under the Civil Hydrography Programme. To download the related bathymetry data go to the Admiralty Marine Data Portal (https://datahub.admiralty.co.uk/portal/apps/sites/#/marine-data-portal). The oil and gas industry site surveys layer shows the geographic location of oil and gas industry site surveys. The metadata for these surveys were collated via the BGS MEDIN Data Archive Centre (DAC). BGS do not hold the data. For further information contact the custodian of the data. For more information, contact BGS Marine Enquiries (offshoredata@bgs.ac.uk ).