This dataset contains a GIS vector polyline of 11,770 2D seismic survey lines undertaken in seas around Ireland. Data includes contractor, line, survey Id, company, survey area name, project code and prefix details. A 2D survey typically contains numerous lines acquired orthogonally to the strike of geological structures (such as faults and folds) with a minimum of lines acquired parallel to geological structures to allow line-to-line tying of the seismic data and interpretation and mapping of structures. The data has been collected in seas around Ireland including the North Atlantic Ocean, Irish Sea, Saint George's Channel, Celtic Sea, North Channel and Inner Seas off the west coast of Scotland. The data has been collected for the period 1965-2015. 2D seismic survey data collection involves sound waves which are bounced off underground rock formations and the waves that reflect back to the surface are captured by recording sensors for later analysis. Seismic surveys are used to produce detailed images of local geology to determine the location and size of possible oil and gas reserves. Data has been collated by the Petroleum Affairs Division as part of its role to maximise the benefits to the Irish State from exploration for and production (E and P) of indigenous oil and gas resources. The dataset is considered an accurate recorded representation of 2D seismic surveys completed and logged by the Petroleum Affairs Division.