This dataset contains polygon extents of all known bathymetry surveys and bathymetry compilations in Australia's marine jurisdiction, including the Australian Antarctic Territory. Each polygon includes metadata identifying attributes, contact details, information on the public availability of data, and (in the case of published data) gridded resolution. The following data sources have been used as inputs: • AusSeabed 'Bathymetry Acquisitions Coverage (Dynamic)' (https://dx.doi.org/10.26186/148613) • AusSeabed 'Bathymetry Compilations Coverage (Dynamic)' (https://dx.doi.org/10.26186/148614) • computed footprints (suffixed by _L0_Coverage) of bathymetry data published through AusSeabed Warehouse Geoserver (https://warehouse.ausseabed.gov.au/geoserver) • computed footprints (suffixed by _BBOX) of bathymetry data published through CSIRO Geoserver (https://www.cmar.csiro.au/geoserver) • manually computed footprints of bathymetry data published through other online repositories: WA Bathymetry Portal (https://dot-wa.maps.arcgis.com/apps/webappviewer/index.html?id=d58dd77d85654783b5fc8c775953c69b), the Australian Ocean Data Network (https://portal.aodn.org.au) and the NSW SEED Portal (https://www.seed.nsw.gov.au) This dataset was generated to enable reporting for Seamap Australia's 'State of Knowledge' functionality (https://seamapaustralia.org/map/), as existing coverage information does not contain metadata on gridding resolution. The dataset is live and will be continually updated as new surveys are conducted and new coverage information becomes available. Gridding resolution will be appended to existing survey extents when historical surveys are published. This dataset is updated regularly (date of last update: 23/05/2025) and will be maintained in perpetuity until such time that the information required for Seamap Australia's 'State of Knowledge' functionality is delivered through an alternative mechanism. Note that a degree of spatial simplification has been conducted to reduce filesize and polygon complexity. All efforts have been made to maintain true survey extent (area-preserving simplification has been used), but polygons may not be representative of the true survey extents, particularly in the case of reported extents from unpublished surveys which cannot be verified.

There is an ongoing need for a national index of bathymetry survey coverage in Australian waters. The Marine National Facility (MNF) is Australia's dedicated blue-water research facility, and collects the largest body of publicly-accessible multibeam bathymetry (MBES) data in Australian waters. MNF survey data is routinely published in a raw (unprocessed) form shortly following MNF survey completion by CSIRO's Geophysical Survey and Mapping (GSM) group (https://www.cmar.csiro.au/data/gsm/). Geoscience Australia's AusSeabed initiative (https://ausseabed.gov.au/) works with CSIRO to make MNF MBES data available as maps and for download in gridded format at resolutions specified by the Australian Multibeam Guidelines (https://www.ausseabed.gov.au/__data/assets/pdf_file/0010/95887/Multibeam-Guidelines_v2.pdf). Once gridded MBES data is published, its survey coverage (spatial footprint) is collated into nationally aggregated bathymetry acquisitions maps (e.g. see https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/bfaac2bc-0c11-4991-b0fa-2a1dc7fd6e61). This spatial resource is important for research, marine managers, industry, and environmental impact assessment sectors as it provides an overview of the state of research knowledge of the physical seafloor environment in key areas of interest within Australia's vast marine estate. There is a considerable lag between MBES data being made available in L2 specialist format (typically ASCII XYZ), and being processed into a gridded format (e.g. GeoTIFF) following the Australian Multibeam Guidelines resolution specifications. This leaves some uncertainty about the location and coverage of more recently collected MBES data that has yet to be processed and publicly released in a gridded format. This dataset is a compilation of MNF voyage tracks (available through the CSIRO data trawler: https://www.cmar.csiro.au/data/trawler/) from the last 5 calendar years. The dataset will be periodically updated to reflect new voyage tracks; and to remove voyage tracks >5 years old. See 'Last Update' timestamp for an indication of currency. This record will be unpublished at such time that an automated process is developed to update national bathymetry survey coverage databases.

This data presents the results of seabed mapping and habitat classification surveys completed in Darwin Harbour during 2011 and 2013 as part of the Northern Territory Government's marine habitat mapping program. This research is a collaboration between Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS), the Department of Land Resource Management (DLRM) and the Darwin Port Corporation. Key objectives are to: - Produce detailed maps of the bathymetry and derived parameters such as slope and rugosity, - Classify the seabed into areas of hard and soft substrate, and, - Produce seabed habitat maps (or seascapes). Key outcomes from the surveys include: 1. Improved understanding of the seabed of Darwin Harbour. The main seabed geomorphic features identified in Darwin Harbour include banks, ridges, plains and scarps, and a deep central channel that divides into smaller and shallower channels. Acoustically hard substrates are found mostly on banks and are associated with rocky reef and sponge gardens, and are often overlain by a thin veneer of sandy sediment. In contrast, plains and channels are characterised by acoustically soft substrates and are associated with fine sediments (mud and sand). 2. Classification of physical seabed properties to produce a Seascape Map for Darwin Harbour. Six seascape classes (potential habitats) were derived using an Iterative Self Organising (ISO) unsupervised classification scheme. These six classes are related to statistically unique combinations of seabed substrate, relief, bedform and presence of sediment veneer (quite often inferred from presence of epibenthic biota).