This dataset contains temperature and salinity data for the Derwent Estuary (Tasmania), including Ralphs Bay and the mouths of the D'Entrecasteaux Channel and Storm Bay. The data were collected on various transects over 2 day periods at 3-monthly intervals, between March 1992 and July 1994. Salinity and temperature were measured as a function of depth using a CTD, at 60 stations representing transects both along and across the estuary, ranging from New Norfolk to the river mouth. Contour plots derived from the data are given in the cited report (see references). The data form the physical component of the Derwent Estuary study, carried out as part of the CSIRO Coastal Zone Program.