This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2021_V01, "Quantifying krill abundance for krill monitoring and management off the Australian Antarctic Territory", which departed Hobart on the 29th January 2021 and returned to Hobart on the 24th March 2021 (AEST). The Simrad EK80 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a maximum range of 1500 m between Hobart and near Mawson station, Antarctica. All frequencies were logged continuously for the extent of the voyage. Acquisition settings (pulse length, power) were varied for the transit and survey portions of the voyage according to science requirements. Specific settings for each time period can be obtained from the GSM voyage report. From 1 Feb, 2021 the 18kHz WBT was replaced with the 18kHz GPT which was run for the remainder of the voyage. A calibration was performed at the survey location on 13 Feb 2021. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 3192 files totalling 295 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 from the Marine National Facility (MNF) RV Investigator Voyage IN2020_V08, titled "SOLACE - Southern Ocean Large Areal Carbon Export: quantifying carbon sequestration in subpolar and polar waters." The voyage took place between December 5, 2020 and January 16, 2021 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 1500 m, at the three study locations and transit to and from Hobart . All frequencies were logged continuously for the extent of the voyage. Logging of "complex samples" occurred daily for one hour. Data are stored in *.raw (6273 files 625 GB) and *.idx (6273 files 63.0 MB) formats at CSIRO. 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 Bluefin voyage BF2019_V01, 'Hydrographic Survey of the Freycinet, Huon and Tasman Fracture Australian Marine Parks' which departed Hobart, Tasmania on the 8th March 2019 and returned to Beauty Point, Tasmania on the 22nd March 2019. CSIRO’s Geophysical Survey and Mapping, Shallow Survey Facility (SSF) was contracted by the Institute for Marine and Antarctic Studies (IMAS) of the University of Tasmania (UTAS) in collaboration with Parks Australia, to undertake a 2 week hydrographic survey of the Freycinet Australian Marine Park to complete surveying of the Park out to approximately 300 m. Depending on weather conditions further surveying of the Huon and Tasman Fracture sites could also be attempted. Two sites, Pedra and South West Cape survey areas, were undertaken for comparison data outside of Marine Park areas. Nick Dando from Geoscience Australia (GA) mobilised their Kongsberg EM2040c Mulitbeam Echosounder (MBES) system onboard the MV Bluefin in Hobart on Thursday and Friday 7-8 March with assistance from Stuart Edwards, Craig Davey and Bernadette Heaney, CSIRO. Divers from IMAS attached the transducer to the hull of the ship. The GA system also included a POSMV navigation system, a Valeport sound velocity profiler (and a spare profiler) Bridge display laptop and Bridge display screen. The Kongsberg EM2040c multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter at the Freycinet, Huon and Tasman Fracture Australian Marine Parks surrounding south and south eastern Tasmania. The EM2040c provides a 1.3° by 1.3° transmit and receive angular resolution respectively. The echosounder's nominal frequency was 300 kHz and was operated in dual swath mode. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. 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 final processed dataset. Instead the data was mapped to the ellipsoid (GPS Height) and thereafter reduced to AHD (Australian Height Datum) using the AusGeoid09 model. 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 reports. Additional data products may be available on request.

This record describes multibeam echosounder data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2020_V08, titled "SOLACE - Southern Ocean Large Areal Carbon Export: quantifying carbon sequestration in subpolar and polar waters." The voyage took place between December 5, 2020 and January 16, 2021 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 while transiting between Hobart and study sites in the Southern Ocean. The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in *.all (364 files 19.7 GB) raw format for bathymetry and backscatter and *.wcd (328 files 14.3 GB) format for watercolumn backscatter at CSIRO. 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 applied to the processed data using RTK/GPS height and the EGM2008 geoid model in Qimera. 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 sub bottom profiler data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2020_V08, titled "SOLACE - Southern Ocean Large Areal Carbon Export: quantifying carbon sequestration in subpolar and polar waters." The voyage took place between December 5, 2020 and January 16, 2021 departing from Hobart (TAS) and arriving in Hobart (TAS). The Kongsberg SBP120 (sub bottom profiler) was used to acquire data containing the specular reflections at different sediment interfaces below the seafloor. The SBP120 provides a 3° by 3° angular resolution. The echosounder's frequency sweep range is from 2.5 to 7 kHz. The SBP120 was logged sporadically for the extent of the voyage. Data are stored in *.raw (1141 files 2.5 GB) raw and *.seg (1140 files 2.5 GB) segy formats at CSIRO. The segy format data had a real time processing stream applied, which applies gain, a gain correction, matched filter with replica shaping, an attribute calculation for instantaneous amplitude and time variable gain. 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 from the Marine National Facility (MNF) RV Investigator Voyage IN2020_V08, titled "SOLACE - Southern Ocean Large Areal Carbon Export: quantifying carbon sequestration in subpolar and polar waters." The voyage took place between December 5, 2020 and January 16, 2021 departing from Hobart (TAS) and arriving in Hobart (TAS). The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter in the shallow waters of Storm Bay. 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 (30 files 8.0 GB) raw format for bathymetry and backscatter and *.wcd (23 files 23.0 GB) formats for watercolumn backscatter at CSIRO. 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 applied to the processed data using RTK/GPS height and the EGM2008 geoid model in Qimera. 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 ME 70 scientific multibeam fisheries echosounder data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2020_V08, titled "SOLACE - Southern Ocean Large Areal Carbon Export: quantifying carbon sequestration in subpolar and polar waters." The voyage took place between December 5, 2020 and January 16, 2021 departing from Hobart (TAS) and arriving in Hobart (TAS). The Simrad ME70 scientific multibeam echosounder acquired acoustic backscatter data through the water column to 200m. The echosounder's frequency range is from 70 kHz to 120 kHz. The ME70 logged sporadically for the extent of the voyage. Data is stored in Simrad *.raw format at CSIRO. There are 273 files totalling 41.2 GB of raw data in this dataset. No processing has been conducted on this data. Additional information regarding this dataset, including the settings used, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes gravity data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2020_V08, titled "SOLACE - Southern Ocean Large Areal Carbon Export: quantifying carbon sequestration in subpolar and polar waters." The voyage took place between December 5, 2020 and January 16, 2021 departing from Hobart (TAS) and arriving in Hobart (TAS). The gravity meter instrument is a MicroG Lacoste Air-Sea II. Data are stored in .ENV (45 files 8.4 MB) and .DAT (45 files 715MB) data files at CSIRO. No wharf ties were undertaken. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report.