This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2021_V02 (SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania), which departed Hobart on the 14th April 2021 and returned to Hobart on the 28th April 2021. The Simrad EK80 wide band transceivers (WBT) 38, 70, 120, 200 and 333 kHz, as well as the EK60 split-beam GPT 18kHz were used to acquire acoustic backscatter data to a range of 1500 m, during the voyage. All frequencies were logged sporadically (only when transiting) for the extent of the voyage. The frequencies were set to passive for the periods when stationary during the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 422 files totalling 40.6 GB of raw data in this dataset. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2018_V07, SOTS: Southern Ocean Time Series Automated Moorings for Climate and Carbon Cycle Studies Southwest Tasmania which departed Hobart on the 20/08/2018 and returned to Hobart on the 25/08/2018. The Simrad EK60 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1500 m, between Hobart and the mooring deployment site and return. All frequencies were logged continuously for the extent of the voyage. The all frequencyies were set to passive for the whole of the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 591 files totalling 19.2 GB of raw data in this dataset. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2019_V02, titled 'SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania; Subantarctic Biogeochemistry of Carbon and Iron, Southern Ocean Time Series site', which departed Hobart on the 14 March 2019 and returned to Hobart on the 5 April 2019. The Simrad EK60 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a 1500 m range, around the southwest of Tasmania. All frequencies were logged continuously for the extent of the voyage. The frequencies were set to passive for periods of the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 2,748 files totalling 91.5 GB of raw data in this dataset. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2017_V02, 'SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania' which departed Hobart on the 17 March 2017 and returned to Hobart on the 28 March 2017. The Simrad EK60 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 0-1500 m, around Southern Ocean. All frequencies were logged continuously for the extent of the voyage. The frequencies were set to passive for the periods during the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are [XXXX] files totalling [XXXX] GB of raw data in this dataset. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2018_E01, Triaxus Sea Acceptance Testing & Calibrations Voyage, which departed Hobart on the 9th June 2018 and returned to Hobart on the 11th June 2018. The Simrad EK60 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 50 m, at the calibration site at White Rock in Storm Bay. Sphere calibrations were performed during this voyage using a 60 mm copper sphere (18, 38, 70 kHz) and 38.1 mm Tungsten Carbide sphere (120, 200, 33kHz). All frequencies were logged for the extent of the calibrations of the voyage. Data are stored in .raw, .bot and .idx format at CSIRO. There are 21 .raw files totalling 422 MB of raw data in this dataset. On-axis calibration processing using EchoView 8 has been conducted on this data. Additional information regarding this dataset is contained in the GSM in2018_e01 EK60 Calibration Report. Additional data products may be available on request.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2018_T01, titled: "Physical and biogeochemical gradients in the East Australian Current." The voyage took place from Hobart (TAS) to Brisbane (QLD) between April 5 and April 14, 2018. The Simrad EK60 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data, between Brisbane and Hobart. All frequencies were logged sporadically for the extent of the voyage. The frequencies were set to passive for the periods of the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 2,175 files totalling 41.7 GB of raw data in this dataset. No processing has been conducted on this data. Data spans 5/04/2018 20:00 until 06/04/2018 06:00 UTC. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2023_V04, International nutrient inter-comparison Voyage (INIV) which departed Hobart on the 05/06/23 and returned to Hobart on the 18/06/23. The Simrad EK60 split beam echosounders for18kHz and Simrad EK80 split beam echosounders for 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1500 m, in the Southern Ocean Southwest of Hobart. All frequencies were logged sporadically for the extent of the voyage. The 70 KHz frequency was set to passive for the periods of the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 2,644 files totalling 59.6 GB of raw data in this dataset. No Processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2018_V07, SOTS: Southern Ocean Time Series Automated Moorings for Climate and Carbon Cycle Studies Southwest Tasmania which departed Hobart on the 20/08/2018 and returned to Hobart on the 25/08/2018. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information between Hobart and the mooring deployment site. The EM710 MKII provides a 0.5° by 1° transmit and receive angular resolution respectively. The echosounder's nominal frequency range is from 40 to 100 kHz. Data are stored in *.all raw format for bathymetry and backscatter at CSIRO. There are 21 files totalling 2.27 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Tide corrections were not applied to the processed data. Processed data has had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2022_V03, "SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania", which departed Hobart on the 4th May 2022 and returned to Hobart on the 15th May 2022 (AEST). The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter in shallow water (<1000m) on the shelf of Tasmania during the transit to and from Hobart. The EM710 MKII provides a 0.5° by 1° transmit and receive angular resolution respectively. The echosounder's nominal frequency range is from 40 to 100 kHz. During IN2022_V03 the frequency range was set from 70 to 100kHz. Data are stored in .all raw format for bathymetry and backscatter and .wcd format for watercolumn backscatter at CSIRO. There are 32 .all files totaling 5.52 GB of raw bathymetry/backscatter data and 32 .wcd files totaling 26.2GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2019_V02, titled 'SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania; Subantarctic Biogeochemistry of Carbon and Iron, Southern Ocean Time Series site', which departed Hobart on the 14 March 2019 and returned to Hobart on the 5 April 2019. The Kongsberg EM710 multibeam echosounder was used to acquire seafloor bathymetry and backscatter information around Southeast Tasmania. The EM710 provides a 0.5° by 1° transmit and receive angular resolution respectively. The echosounder's nominal frequency range is from 70 to 100 kHz. Data are stored in *.all raw format for bathymetry and backscatter at CSIRO. There are 98 files totalling 4.92 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format is corrected for motion and position. Tide corrections were not applied to the processed data. Processed data had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.