Conductivity, temperature and pressure were measured continuously at Georgia Coastal Ecosystems LTER sampling location GCE9_Hydro (Altamaha River near Rockdedundy Island, Georgia) from 01-Jan-2007 through 07-Nov-2007. Observations were logged at 30 minute intervals by moored Sea-Bird Electronics MicroCAT 37-SM data loggers and downloaded approximately semi-monthly. Salinity, depth and sigma-t (density anomaly) were calculated from the measured parameters using standard UNESCO algorithms. This data set was collected as part of the GCE-LTER Project continuous salinity, temperature and water level monitoring program.