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 IN2018_V06, which departed Hobart on the 22-Nov-2018 and returned to Hobart on the 19-Dec-2018. The Simrad EK60 split beam echosounders [12], 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of [range] m, Huon, Tasman Fracture Marine Parks and the St Helens seamount, Tasmania.. All frequencies were logged continuously for the extent of the voyage The frequencies were] set to passive for the periods when tracking towed bodies using USBL. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 4690 files totalling 90 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 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_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_V05, titled "Untangling the causes of change over 25 years in the southeast marine ecosystem (SEA-MES Voyage 1). The voyage took place between June 28, 2023 and July 30, 2023 (AEST), departing from Hobart and returning to Hobart. The Simrad EK60 split beam echosounders for 18kHz 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 1500m, between Hobart and Sydney. All frequencies were logged continuously for the extent of the voyage. The 70 & 120 kHz frequencies were set to passive for periods of the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 809 files totalling 68.4 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 IN2023_V03, SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania which departed Hobart on May 12, 2023 and returned to Hobart on the May 25, 2023. The Simrad EK60 split beam echosounders for 18kHz 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, between Hobart, the SOTS location and while on site. All frequencies were logged continuously for the extent of the voyage. There was a dedicated acoustic survey over the Patience Seamount while transiting to SOTS and also some opportunistic noise data collection to compare EK60 and EK80 noise levels. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 1130 files totalling 53 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 IN2025_V02, ' SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania ' which departed Hobart on the 26th March and returned to Hobart on the 14th April 2025. The Simrad EK80 split beam echosounders for 18, 38, 70 120, 200 were used to acquire acoustic backscatter data to a range of 1500 m. All of these frequencies were logged continuously for the extent of the voyage with the exception of periods of mooring triangulations. The 333 kHz was set to passive for the duration of the voyage due to a known issue with the transducer. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 807 files totalling 76 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 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 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.