This record describes multibeam echosounder data collected on RV Investigator voyage IN2022_V02, titled "Sedimentation at its extreme: how powerful are submarine caldera-forming eruptions (Kermadec arc)?" The voyage took place between March 15, 2022 and April 19, 2022 (AEST), departing from Hobart and returning to Hobart. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter in shallow water (<500m) on the shelf of Tasmania and a small portion of the New Zealand continental shelf. 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_V02 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 37 .all files totaling 8.15 GB of raw bathymetry/backscatter data and 31 .wcd files totaling 48.7GB 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 scientific split-beam echosounder data collected on the RV Investigator voyage IN2022_V02, titled "Sedimentation at its extreme: how powerful are submarine caldera-forming eruptions (Kermadec arc)?" The voyage took place between March 15, 2022 and April 19, 2022 (AEST), departing from Hobart and returning to Hobart. The main area of survey was the Kermadec arc off of New Zealand. 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 and to full ocean depth while at the New Zealand/Kermadec survey area. All frequencies were logged continuously for the extent of the voyage, except for a period of time between 26/03/2022 05:00 and 29/03/2022 11:05 UTC when all data recording was mandated to be suspended. The 70kHz was occasionally set to passive while in shallow water to limit interference with the EM710 multibeam. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 1773 files totalling 110 GB of raw data in this dataset. Transit data between Hobart and the New Zealand EEZ were post-processed for the Integrated Marine Observing System (IMOS) and posted to the Australian Ocean Data Network (AODN) Portal. 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 IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The Kongsberg EM712 multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter data. The EM712 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 .kmall raw format for bathymetry and backscatter and .kmwcd format for watercolumn backscatter at CSIRO. There are 131 files totalling 17.8 GB of raw data and 131 files totalling 92.9 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall 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. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The EM124 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in .kmall raw format for bathymetry and backscatter and .kmwcd format for watercolumn backscatter at CSIRO. There are 1044 files totalling 140 GB of raw data and 1044 files totalling 186 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall 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. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2025_V04, titled "Untangling the causes of change over 25 years in the southeast marine ecosystem - Voyage IV." The voyage took place between May 27, 2025 and June 28, 2025 (AEST), departing from Hobart and returning to Hobart. The Kongsberg EM712 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter between Hobart and Eden. The EM712 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 .kmall raw format for bathymetry and backscatter and .kmwcd format for watercolumn backscatter at CSIRO. There are 1188 files totalling 255 GB of raw data and 1183 files totalling 1.32 TB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall 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. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on IN2025_V05, 'Eruption, destruction and seafloor ecosystem recovery – Tonga 2022 eruption of the century', which departed Hobart on 10 Aug and ended in Brisbane on 01 Oct 2025 (local). The voyage’s first leg transited from Hobart to Nuku’alofa (10–19 Aug 2025), where science participants boarded. A mid-voyage transfer occurred on 05 Sep, and all science personnel disembarked in Nuku’alofa on 23 Sep before the final transit to Brisbane (23 Sep–1 Oct 2025). The EM2040MK2 provides a 0.4 degree by 0.7 degree angular resolution. The echosounder's nominal frequency is 400 kHz (with a range of 200-700 kHz) and it operated in dual swath mode. Data are stored in .kmall raw format for bathymetry and backscatter and .kmwcd format for watercolumn backscatter at CSIRO. There are 71 files totalling 26 GB of raw data and 71 files totalling 203 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall 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. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2022_V09, titled "Valuing Australia’s new Gascoyne Marine Park." The voyage took place between 0000 November 19, 2022 and 0700 December 19, 2022 (UTC), departing from Fremantle and returning to Fremantle. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter throughout the voyage in areas with water depths deeper than ~800m including areas within the Gascoyne Marine Park. The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in *.all raw format for bathymetry and backscatter at CSIRO. There are 809 files totalling 46.3 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. 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 grids in geotiff format. Additional information regarding this dataset, including 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 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 Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter around Macquarie Island and during transit to the survey area. The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in .all raw format for bathymetry and backscatter and .wcd format for watercolumn backscatter at CSIRO. There are 667 files totalling 32.4 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 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 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 IN2025_V04, titled "Untangling the causes of change over 25 years in the southeast marine ecosystem - Voyage IV." The voyage took place between May 27, 2025 and June 28, 2025 (AEST), departing from Hobart and returning to Hobart. The EM124 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in .kmall raw format for bathymetry and backscatter and .kmwcd format for watercolumn backscatter at CSIRO. There are 20 files totalling 1.85 GB of raw data and 20 files totalling 4.0 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall 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. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2024_V03, titled "Untangling the causes of change over 25 years in the southeast marine ecosystem (SEA-MES Voyage 2)." The voyage took place between May 01, 2024 and May 31, 2024 (AEST), departing from Hobart and returning to Sydney. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter between the shelf areas of eastern Australia from Hobart, TAS to Sydney, NSW. The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in .all raw format for bathymetry and backscatter and .wcd format for watercolumn backscatter at CSIRO. There are 62 files totalling 6.01GB 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. GPS tide was computed using PosMV data and then set to vertical datum EGM2008 model for approximate mean sea-level 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 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.