This dataset comprises derived bathymetric isobaths (depth contour lines) generated from the Geoscience Australia (GA) AusBathyTopo 250m 2024 gridded bathymetric dataset ( https://dx.doi.org/10.26186/150050). The AusBathyTopo 250m grid provides a high-resolution terrain model for Australia, covering ocean and land areas from 92°E to 172°E and 8°S to 60°S at a resolution of 250 metres. The bathymetric contours are clipped to the boundaries of the Australian Exclusive Economic Zone (EEZ: https://amsis-geoscience-au.hub.arcgis.com/datasets/geoscience-au::exclusive-economic-zone-limits/about), and includes all regions including and below Mean Sea Level (MSL).

Four contour datasets are provided:

1) 100 m intervals: full EEZ coverage.

2) 5 m intervals: shallow regions between 0–200 m depth (nominally the Australian continental shelf and shallow oceanic features).

3) 1 m intervals: shallow regions between 0–200 m depth.

4) Composite product: Multi-resolution contours with full EEZ coverage, including:

• 2 m intervals for depths 0–30 m.

• 5 m intervals for depths 30–100 m.

• 10 m intervals for depths 100–200 m.

• 50 m intervals for depths 200–2,000 m.

• 100 m intervals for depths 2,000–8,000 m.

These contour datasets are intended for use in marine spatial planning, mapping visualisation, and broad-scale analysis. Due to the smoothing procedures applied during their creation the are not suitable for engineering or high-precision applications.

The contours presented through the Web Mapping Services (WMS) linked to this record are optimised for visualisation purposes and have been simplified using a tolerance of 10 meters for efficient rendering in mapping applications. For users requiring full-resolution data, the download packages include the original, unsimplified contour products.