The Bridport Sand Formation is known from exposures in Dorset, Somerset and Gloucestershire and from the subsurface in numerous boreholes. It is also present offshore in the Portland–South Wight Basin, a sub-basin of the Wessex Basin. It reaches a maximum thickness of over 135 m in the Kimmeridge-3 well, in the onshore part of the Portland–South Wight sub-basin. It thins northwards from Dorset onto the Mendips axis, where it is missing. It reappears to the north of the axis.
