This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2017_C01, 'GAB deep water geological and benthic eoclogy program' which departed Hobart on the 11 April 2017 and returned to Hobart on the 28 April 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 1500 - 5000 m, around the GAB. All frequencies were logged continuously for the extent of the voyage. The frequency 18kHz was set to passive for periods during the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 606 files totalling 34.8 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 sea trial IN2015_E06, which consisted of three legs, 5-8 Oct 2015, 9-11 Oct 2015 and 12-16 Oct 2015, in and out of Hobart. The Simrad EK60 split beam echosounders, 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data. All frequencies were logged for the extent of the voyage. Sounder calibrations were undertaken. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 1457 files totalling 25.3 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_E04, Trials voayge, which departed Hobart on the 7th of December 2017and returned to Hobart on the 11th of December 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 1500 m, off the southeast coast of 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 94 .raw files totalling 7.95 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_V01, Detecting Southern Ocean change from repeat hydrography, deep Argo and trace element biogeochemistry & CAPRICORN which departed Hobart on the 11 January 2018 and returned to Hobart on the 22 February 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 66°S. All frequencies were logged continuously for the extent of the voyage but no personnel were on board to monitor the acquisition. Data are stored in .raw, .bot and .idx format at CSIRO. There are 1041 .raw files totalling 94.8 GB of raw data in this dataset. Processing has been conducted on this data for the return transit from 66S to Hobart.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2017_V03, 'Sampling the abyss: latitudinal biodiversity patterns along the base of Australia’s eastern continental margin' which departed Bell Bay on the 15 May 2017 and returned to Brisbane on the 16 June 2017. The Simrad EK60 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data when possible. All frequencies were logged mainly when transitting between sites as all ship acoustics were turned off when listening for beacon signals on most operations. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 45.5 GB of raw data in this dataset. Amy Nau, will be processing 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 IN2016_V02, which departed Hobart on the 14th-March-2016 and returned to Hobart on the 16th-April-2016. 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. All frequencies were logged continuously 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 780 files totaling 70.6 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_V07, [FOCUS] which departed Hobart on the 15/11/23 and returned to Hobart on the 20/12/23. 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, around the Antarctic Circumpolar Current in the Southern Ocean, South of Hobart. All frequencies were logged continuously for the extent of the voyage. The 33 KHz and 70 KHz frequencies were set to passive for periods of the voyage. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 1806 files totalling 176 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 IN2024_E01, 'Trials and Calibrations' which departed Hobart on the 28th October and returned to Hobart on the 6th November 2024. The Simrad EK80 split beam echosounders for 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1500 m. All frequencies were not logged continuously for the extent of the voyage due to the priority of Sea Acceptance Tests (SAT) for the newly installed seafloor mapping systems. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 1265 files totalling 143 GB of raw data in this dataset. NOTE: On the 5th November 2024 five transducers (18, 38, 70, 120, and 200 kHz) were calibrated using the EK80 WBTs in continuous wave (CW) mode. Due to a fault with the 333 kHz that frequency was not calibrated. 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.