This record describes multibeam echo sounder data collected during field experiments on RV South Cape survey SC2020_V01. CSIRO’s Oceans & Atmosphere Shallow Survey Facility (SSF) undertook multibeam water column experiments over an artificial seep deployed near Kingston Beach, southern Tasmania. The goal of the experiments was to characterize the utility of high frequency multibeam water column data for the detection of gas seeps in very shallow water (<20 m). These experiments were aligned to inform the ANLEC R&D Carbon Capture and Storage Marine Monitoring and Verification (MM&V) project (ANLEC R&D 7-0816-0305) on the application of multibeam water column data for the detection of gas seeps in shallow water as a regular monitoring tool. The Geophysical Survey & Mapping team single-head EM2040C multibeam was mobilised on RV South Cape and bathymetry and water column data were collected over a custom-built bubble release system to simulate a shallow water gas seep at a test site near Kingston Beach, southern Tasmania. The EM2040 provides a 1.3° by 1.3° transmit and receive angular resolution respectively. Data were acquired at 300kHz frequency using single swath mode, short CW pulse, beam spacing set at equidistant and sector coverage set to 65° port and starboard (total coverage 130°). Data are stored in *.all raw format for bathymetry and backscatter and in *.wcd format for water column backscatter at the CSIRO. There are 397 *.all and 373 *.wcd files totaling 129 GB of raw multibeam data in this dataset. Sound velocity profiles were applied to the data during data acquisition. Bathymetry data contained in *.all format have been corrected for motion and position. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report (sc2020_v01_Bubble_experiments_CCS_Rev_1.pdf). Water column data were post-processed using custom MATLAB workflows. A variety of workflow methods were tested, with the processing results of each available in *.txt and *.jpg format. Additional data products may be available on request.

This record describes multibeam echosounder data collected on RV Linnaeus voyage LI2019_V01, 'Ningaloo Deepwater Reefs Hydrographic Survey' which departed Hillary's Boat Harbour, Perth, WA on the 15th March 2019 and concluded at Coral Bay, WA on the 29th March 2019. The Kongsberg EM2040c multibeam echosounder (single transceiver) was used to acquire seafloor bathymetry and backscatter information (and watercolumn backscatter) offshores of Ningaloo Reef, WA. Transit data to and from nightly anchorages has also been recorded. The EM2040c provides a 1.3° by 1.3° transmit and receive angular resolution respectively (single transceiver). The echosounder's nominal frequency range was 200 kHz and it 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. There are 140 files totalling 32.5 GB of raw .all data, and 103 files totalling 178 GB of raw .wcd in the 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 applied to the processed data in Caris using a GPS Tide based on the Applanix PosMV and Marinestar G4+ Ellipsoidal ht and thereafter reduced to AHD (Australian Height Datum) using a 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 report. Additional data products may be available on request. The raw data is offline but is 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 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 Dual-Head Kongsberg EM2040c multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter at 3 focused site north of Cairns. An additional site, Lowry passage, was also systematically surveyed with the system. The EM2040c provides a 1.3 degree by 1.3 degree angular resolution. The echosounder's nominal frequency is 300 kHz and it operated in dual-head single swath mode. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 701 files totalling 174 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. Predicted tides calculated in AusTides 2022 were applied to the processed data relative to MSL. 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 voyage BF2022_V01 aboard the AMC's vessel the Bluefin. The vessel departed Beauty Point on the 28/02/2022 and returned to Beauty Point on the 21/03/2022. The Kongsberg EM2040c multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter. The surveyed areas include Zeehan Marine Park, west of King Island and the Franklin Marine Park, west of Marrawah (NW Tasmania). A total surveyed area was 1026.2 km² not (including transits) comprising Zeehan Marine Park 726 km² and Franklin Marine Park 300.2 km². The EM2040c provides a 1.3 degree by 1.3 degree angular resolution. The echosounder's nominal frequency is 300 kHz and it operated in dual swath mode. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. Raw data files include: - 751 *.all files totalling 237GB - 728 *.wcd files totalling 1.55TB Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Processed data was corrected to MSL utilising the EGM2008 geoid model. Processed data had outliers removed. Processed line data are available in *.gsf 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 IN2018_C01, 'RAN Hydrographic Survey' which departed Hobart on the 28th May 2018 and returned to Hobart on the 8th June 2018. The overall focus for this survey was to conduct a modern survey in the primary shipping route through Bass Strait and to To facilitate safe navigation for international and coastal shipping. The Kongsberg EM2040c multibeam echosounder (dual transceivers) was used to acquire seafloor bathymetry and backscatter information (and watercolumn backscatter) near Wilson's Promontory in Bass Strait and during the transit from and to Hobart. The EM2040c provides a 1.3° by 1.3° transmit and receive angular resolution respectively. The echosounder's nominal frequency was 300 kHz and it 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. There are 361 files totalling 60.1GB of raw .all data, and 243 files totalling 391 GB of raw .wcd in the 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 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. The raw data is offline but is available on request.

This record describes the End of Voyage (EOV) data archive from the Marine National Facility (MNF) 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. There were seven projects on this voyage: • Microplastics in the food chain: impact on the microbial and planktonic organisms; • Linking the Biological Carbon Pump flux to microbial colonisation of sinking particles in the Southern Ocean in the Coral Sea; • Dinoflagellates & broader planktonic assemblage observation; • BGC-Argo Float Deployment; • Cosmic Ray Measurements; • Carbon Sampling; and • Flow cytometric classification of the phytoplankton community across Australia’s top end For further information please refer to the voyage documentation links. Instruments used and data collected include: Regular measurements: Lowered ADCP (LADCP), Acoustic Doppler Current Profiler (ADCP; 75, 150 KHz ), Greenhouse Gas Analysers (Picarro), Cloud Condensation Nuclei counter (CCN), Condensation Particle Counters (CPC), Disdrometer, Radon Sensor, Scanning Mobility Particle Sizers (SMPS), CTD, Hydrochemistry, Fisheries Echosounder (EK60, EK80), Multibeam Echosounder (EM710, EM122), Sub-bottom Profiler (SBP120), GPS Positioning System, Thermosalinographs (TSG), Fluorometer, Oxygen optode, Infrared Sea Surface Temperature Autonomous Radiometer (ISAR), pCO2, Gravimeter, Multiangle Absorption Photometer (MAAP), Ozone Sensor, Nephelometer, Atmospheric Temperature, Humidity, Pressure, Wind and Rain sensors, Photosynthetically Active Radiation (PAR) sensor, Precision Infrared Radiometer (PIR), Precision Spectral Pyranometer (PSP), Starboard and Portside Radiometers, Air Sampler,Weather Radar. Voyage-specific measurements: Cosmic Ray Detector, Underwater Bioluminescence Assessment Tool (UBAT), Multiple Plankton Sampler (HydroBIOS Multinet). The archive for the IN2021_T01 EOV raw data is curated by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart, with a permanent archive at the CSIRO Data Access Portal (DAP, https://data.csiro.au/dap/), providing access to voyage participants and processors of the data collected on the voyage. All voyage documentation is available electronically to MNF support via the local network. Access to voyage documentation for non-CSIRO participants can be made via NCMI_DataLibrarians@csiro.au.