The data set comprises 2193 profiles of turbidity from an area of the Severn Estuary (UK) between the Shoots and Bridgwater Bay between 1974 and 1978. The data were collected as analogue records of continuous vertical profiles on a time series cross-section basis, where possible, over 13.5 hours from a drifting ship. All measurements were collected between 0 m and 39 m depth. The data coverage is derived from 172 stations along 17 survey lines, the density of coverage varying between 1 and 99 records per station. Each analogue record was digitised as approximately 200 pairs of XY coordinates. The X ordinates were then converted to depth (in metres) using a depth calibration and the Y ordinates to parts per million (PPM) of sediment using siltmeter calibration data. The Fluid Mud data bank was designed by the (former) Institute of Oceanographic Sciences (IOS) Taunton, UK, and the data were originally stored at IOS on a PDP 11 computer. They were then moved to an Oracle RDBMS at the British Oceanographic Data Centre (BODC) and stored as the Bristol Channel Suspended Sediments Data Bank.