The Huon Estuary Study was undertaken by CSIRO Marine Research between 1996 and 1998. The Huon Estuary is in South Eastern Tasmania. This record references the CTD data from both the spatial (HES) and the weekly monitoring (CM) surveys of the Huon Estuary Study. For the spatial (HES) surveys this includes the raw, intermediate, processed and calibrated data. The record also references the software used to process this data together with the technical reports written in support of the datasets. Two ctd profilers were utilized during the spatial surveys, their deployment during the spatial surveys is described in a technical report CTD Data From the Spatial Surveys of the Huon Estuary, OMR-121/117. A technical report on the performance of the seabird ctd is Sea-Bird CTD Performance in a Salt-Wedge Estuary, OMR-116/117. For the weekly monitoring (CM) surveys only preliminary processing has been undertaken. A readme_cont_ctd.txt file describes the processing routine followed for the weekly monitoring surveys. This dataset has not been calibrated. There are also other problems with the weekly monitoring ctd data especially in terms of depth registration (see Lineage below). CTD deployment information (not the actual data) is stored in the project database which is described by the 'Huon Estuary Study 1996/1998 - Database' metadata record. A number of CTD's were also deployed during the Physical Snapshot Surveys (see Marlin record 'Huon Estuary Study 1996/1998 - Physical Snapshot Survey Data') These ctd's were quickly deployed, the data was not processed and they form part of the snapshot dataset along with underway data collected on the same day. For these reasons this data are not referenced by this metadata record and does not form part of the HES CTD dataset.