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 This record will be unpublished at such time that an automated process is developed to update national bathymetry survey coverage databases.