This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2020_V09 (SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania), which departed Hobart on the 27th August 2020 and returned to Hobart on the 12th September 2020. In addition to the tasks at the SOTS site the voyage also recovered a Rintoul mooring that was deployed during IN2020_V05. The Simrad EK80 wide band transceivers (WBT) 18, 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. Note: the EK80 18kHz WBT failed at 12:06 on the 28th August 2020 (UTC) and was no longer used for the voyage. The 18kHz transducer was changed over to the EK60 GPT for the remainder of the voyage (in place of the 18kHz WBT). Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 291 files totalling 27.7 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 high-precision wide-band echosounder data collected on the RV Investigator voyage IN2020_V06, titled "Probing the Australian-Pacific Plate Boundary: Macquarie Ridge in 3-D." The voyage took place between October 8 and November 3, 2020 departing from Hobart (TAS) and arriving in Hobart (TAS). The Simrad EK80 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1,500 m, around Macquarie Island and from Hobart transit. All frequencies were logged for the extent of the voyage, except where required to turn off for operational requirements. The frequencies were set to active for the whole period of the voyage. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 818 files totalling 78.1 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 IN2020_E01 (Trials and Calibration) which departed Hobart on the 29th July 2020 and returned to Hobart on the 6th August 2020. The purpose of this voyage was to undertake post port-period equipment calibrations and commissioning, sea trials and personnel training. The Simrad EK80 wide band transceivers (WBT) 18, 38, 70, 120, 200 and 333 kHz and the EK60 split-beam GPT 333 kHZ were calibrated at the start of this voyage at anchor in the Derwent Estuary on July 29, 2020. The EK80 WBTs were calibrated using default settings for both CW and FM modes. The EK80 system was then used to acquire acoustic backscatter data to a range of 1500 m for the remainder of the voyage offshore to the southeast of Tasman Peninsula. The EK60 split-beam GPTs for 18, 70, 120 and 200kHz were calibrated at anchor in the Derwent Estuary at the end of the voyage on August 6th, 2020. All frequencies were logged sporadically for the extent of the voyage. The frequencies were set to passive for periods during the voyage when conducting other system calibrations. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 1,061 files totalling 99.9 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_E01 (Trials and Calibration) which departed Hobart on the 10th November 2021 and returned to Hobart on the 14th November 2021. The purpose of this voyage was to undertake annual equipment calibrations and commissioning, sea trials and personnel training. The Simrad EK80 wide band transceivers (WBT) 18, 38, 70, 120, 200 and 333 kHz and the EK60 split-beam GPT 18, 70, 120, 200 and 333 kHz were calibrated at the start of this voyage at anchor in the Derwent Estuary on the 10th November 2021. The EK80 WBTs were calibrated using default settings for both CW and FM modes. The EK80 system was then used to acquire acoustic backscatter data to a range of 1500 m for the remainder of the voyage offshore to the southeast of Tasman Peninsula. All frequencies were logged sporadically for the extent of the voyage. The frequencies were set to passive for periods during the voyage when conducting other system calibrations. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 289 files totalling 25.7 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_E02, to calibrate and commission new, upgraded and existing critical equipment (with sea trials and personnel training) onboard RV Investigator for upcoming voyages in the 2021 schedule and beyond. The primary objectives for this voyage were testing the Deep Corer winch stream and respool, Trawling winch calibration, CTD winch 1 & 2 calibrations, HOTS commissioning and Heave Compensation testing, and Deep Towed Camera trial and calibration. The voyage took place between November 20 and November 28, 2021, departing from Hobart (TAS) 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 1500 m, around east of Tasmania and near Freycinet Marine Park. All frequencies were logged continuously for the extent of the voyage, except 70kz which was set to passive in shallow environments. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 488 files totalling 11.5 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 IN2021_E04, to calibrate and commission new, upgraded and existing critical equipment (with sea trials and personnel training) onboard RV Investigator for upcoming voyages in the 2021 schedule and beyond. The primary objective for this voyage were testing Seismic Systems. The voyage departed Hobart PW04 on the 15/12/2021 and returned to Hobart PW04 on the 20/12/2021. 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 region of South East Tasmania. All frequencies were logged continuously for the extent of the voyage. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 210 files totalling 10.1 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 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 Simrad EK60 split beam GPT for 18kHz and Simrad EK80 split beam WBTs for 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1500 m during transits. All frequencies were logged continuously for the extent of the voyage, except for periods of mooring recovery/deployment when all acoustic systems were mandated to be suspended to communicate with the mooring beacons. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 436 files totalling 41.5 GB of raw data in this dataset. 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 collected on RV Investigator voyage IN2022_V07, HALO - Halimeda bioherm Origins, function and fate in the northern Great Barrier Reef." The voyage took place between August 15, 2022 and September 7, 2022 (AEST), departing from Brisbane and returning to Cairns. Piggyback project: Dinoflagellates & broader planktonic assemblage observation. 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. The system was not active during shallow water reef operations, this allowing multi-beam echosunder seabed mapping systems to function optimally. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 1244 files totalling 38.6 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 IN2022_T01, titled "Transit: Cairns to Darwin 2022." The voyage took place between September 11, 2022 and September 17, 2022 (AEST), departing from Cairns and returning to Darwin. The Simrad EK60 split beam echosounders for 18 kHz 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 250 m (shallow water) or 1500 m (deep water) between Cairns and Darwin. All frequencies were logged continuously for the extent of the voyage. The 70 and 120 kHz frequencies were set to passive for the periods of the voyage due to interference with the EM710. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 496 files totalling 26.3 GB of raw data in this dataset. 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 IN2022_V06, titled "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27 degrees South." The voyage took place between July 14 and July 30, 2022 (AEST), departing from Brisbane and returning to Brisbane. 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 1,500 m, around Brisbane 27 degrees South. All frequencies were logged continuously for the extent of the voyage, except when asked to switch off for mooring activities. Occasionally, the 70kHz & 120kHz frequencies were set to passive for the periods of shallow mapping with EM710, and ADCP interference requests from the chief scientist, but all other frequencies wer set to active during the voyage. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 877 files totalling 40 GB of raw data in this dataset. No post 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.