This record describes multibeam echosounder data collected on RV Investigator voyage IN2021_T01, Brisbane to Darwin Transit which departed Brisbane (QLD) on the 11 Jun and returned to Darwin (NT) on the 22 Jun 2021. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information along the transit generally in depths shoal of 1000m. 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 raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 271 files totalling 58.5 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. EGM2008 geoid seperation model was 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 IN2021_T01, Brisbane to Darwin transit which departed Brisbane (QLD) on the 11 Jun and returned to Darwin (NT) on the 22 Jun 2021. 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 250-1500 m, for the duration of the transit. All frequencies were logged continuously for the extent of the voyage. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 244 files totalling 23.8 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.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2021_T01, Brisbane to Darwin Transit which departed Brisbane (QLD) on the 11 Jun and returned to Darwin (NT) on the 22 Jun 2021. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry and backscatter information along the deep water leg of the transit up the East Coast of QLD. 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 164 files totalling 12.1 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. EGM2008 geoid separation model was applied to the processed data set. 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 on RV Investigator voyage IN2021_T01, Brisbane to Darwin Transit which departed Brisbane (QLD) on the 11 Jun and returned to Darwin (NT) on the 22 Jun 2021. 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 continuously for the extent of the voyage except for certain operations. Data are stored in *.raw (8,040 files 4.10 GB) raw and *.seg (8,191 files 4.02 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 gravity data collected on RV Investigator voyage IN2021_T01, Brisbane to Darwin Transit which departed Brisbane (QLD) on the 11 Jun and returned to Darwin (NT) on the 22 Jun 2021. The gravity meter instrument is a MicroG Lacoste Air-Sea II. Data are stored in .ENV and .DAT data files at CSIRO. There are 28 files totalling 212 MB of raw data in this dataset. Wharf tie[s] were undertaken at Brisbane and Darwin using a Scintrex Autograv CG-5. Wharf tie data can be found in Darwin_wharf_tie_2021_06_26.TXT, which is stored with the raw data. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report.

This record describes the Acoustic Doppler Current Profiler (ADCP) data collected from the Marine National Facility RV Investigator voyage IN2021_T01, titled: "Transit: Brisbane to Darwin." The voyage took place from Brisbane (QLD) to Darwin (NT) between June 10th (AEST) and June 23rd (ACST), 2021. Data were collected during in2021_t01 for the duration of the voyage. Data were collected using UHDAS and post-processed using CODAS. Both the RDI Ocean Surveyor 150kHz ADCP and the RDI Ocean Surveyor 75kHz ADCP were run in narrowband. Internal triggering was used. The drop keel was at 7.2m below the waterline for the duration of the voyage. See the voyage computing and electronics report for more details regarding data acquisition. This dataset was processed (quality-controlled), and then archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC).

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2021_T01, titled: "Transit: Brisbane to Darwin". The voyage took place between June 9 to June 23 2021 departing Brisbane and arriving in Darwin. Data for 12 deployments were acquired using the Sea-Bird SBE911 CTD #24, fitted with 36 twelve litre bottles on the rosette sampler. Sea-Bird-supplied calibration factors were used to compute the pressures and preliminary conductivity values. CSIRO -supplied calibrations were applied to the temperature data. The data were subjected to automated QC to remove spikes and out-of-range values. The final conductivity calibration was based on a single deployment grouping. The final calibration from the primary sensor had a standard deviation (SD) of 0.0033235 PSU, outside our target of ‘better than 0.002 PSU’. The standard product of 1 decibar binned averaged were produced using data from the primary sensors. The dissolved oxygen data calibration fit had a SD of 0.64275 μM. The agreement between the CTD and bottle data was good. PAR, upward and downward facing Teledyne Lowered Acoustic Doppler Current Profilers (LADCP), Wetlabs C-Star Transmissometer, ECO Chlorophyl and Scattering, CDOM, and UBAT sensors were also installed on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage Voyage IN2021_T01, titled "Transit Brisbane-Darwin." The voyage took place between June 12 and June 23, 2021 departing from Brisbane (QLD) and arriving in Darwin (NT). . Hydrology samples were collected from Niskin bottles sampled at various depths during Conductivity-Temperature-Depth (CTD) deployments. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. This dataset has been archived at the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes the Underway (UWY) data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2021_T01, titled "Transit Brisbane-Darwin." The voyage took place between June 12 and June 23, 2021 departing from Brisbane (QLD) and arriving in Darwin (NT). Standard Underway data is continuously recorded, consisting of: (1) Navigation data (NAV): Latitude, Longitude, Speed, Heading, Course Over Ground, Gyros, and Doppler Log (dual GPS instrument). (2) Thermosalinograph (TSG): Water Salinity, Flow-Rate, Temperature, Fluorescence, pCO2 and Optode/Oxygen. (3) Atmospheric (MET): Humidity, Wind Speed and Direction (vane and ultrasonic), Radiometer/Sea Surface Temperature, Pyranometer/Solar Radiation, Photosynthetically Active Radiation (PAR), Air Temperature, Air Pressure, Rain, Ozone and Trace Gases (port and starboard instruments). The quality-controlled RV Investigator underway meteorological and SST data are supplied to the IMOS AODN where they are publicly available at the "Ships of Opportunity" Thredds server (http://thredds.aodn.org.au/thredds/catalog/IMOS/SOOP/SOOP-ASF/VLMJ_Investigator/catalog.html) for research. From there, they are downloaded by NOAA for their In Situ Quality Monitoring web site (iQUAM2) and made available for satellite SST validation. The SBE 38 SST data are used within the Australian Bureau of Meteorology for real-time satellite SST validation and ingested into real-time SST analyses which are then used as the boundary condition for Numerical Weather Prediction models. The meteorological and SST data are uploaded onto the Global Telecommunications System (GTS) for global dissemination to Meteorological Agencies, and separately supplied to the SAMOS (http://samos.coaps.fsu.edu/html/) Project for air-sea flux research. The real-time SBE 38 SST data are currently (2017) used in the following data products (accessed via the GTS): • International Comprehensive Ocean-Atmosphere Data Set (ICOADS R3.0) (http://icoads.noaa.gov/) • NOAA NCEI Extended Reconstructed Sea Surface Temperature version 4 (ERSST.v4) (https://www.ncdc.noaa.gov/data-access/marineocean-data/extended-reconstructed-sea-surface-temperature-ersst-v4) • Hadley Centre SST Data Set (HadSST3) (http://www.metoffice.gov.uk/hadobs/hadsst3/) • Global Ocean Surface Underway Data (GOSUD) Project (http://www.gosud.org/) • Bureau of Meteorology daily and weekly SST analyses (http://www.bom.gov.au/marine/sst.shtml) • NOAA NCEI “Reynolds” daily global OISST analysis (https://www.ncdc.noaa.gov/oisst) • NASA JPL “MUR” 1 km daily global SST analysis (https://mur.jpl.nasa.gov/) • UK Met Office “OSTIA” daily global SST analysis (http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html) • CMC daily global SST analysis • Ourocean “G1SST” global daily 1 km SST analysis (https://ourocean.jpl.nasa.gov/SST) As part of the underway data gathering system, other datasets are produced (e.g., pCO2, ISAR SST) which are processed separately and have their own metadata records. Data are recorded at 5 second intervals. Near real-time data are available via the link "Visualisation tool for Underway Data." This dataset has been processed and archived within the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart (TAS). Data are available at time intervals of 5 sec (NetCDF format), 10 sec and 5 min (ASCII format). Additional information regarding this dataset is contained in the Voyage Summary and/or the Data Processing Report for this voyage.