This article reports Australia's first confirmed ancient underwater archaeological sites from the continental shelf, located off the Murujuga coastline in northwestern Australia. Details on two underwater sites are reported: Cape Bruguieres, comprising > 260 recorded lithic artefacts at depths down to −2.4 m below sea level, and Flying Foam Passage where the find spot is associated with a submerged freshwater spring at −14 m. The sites were discovered through a purposeful research strategy designed to identify underwater targets, using an iterative process incorporating a variety of aerial and underwater remote sensing techniques and diver investigation within a predictive framework to map the submerged landscape within a depth range of 0-20 m. The condition and context of the lithic artefacts are analysed in order to unravel their depositional and taphonomic history and to corroborate their in situ position on a pre-inundation land surface, taking account of known geomorphological and climatic processes including cyclone activity that could have caused displacement and transportation from adjacent coasts. Geomorphological data and radiometric dates establish the chronological limits of the sites and demonstrate that they cannot be later than 7000 cal BP and 8500 cal BP respectively, based on the dates when they were finally submerged by sea-level rise. Comparison of underwater and onshore lithic assemblages shows differences that are consistent with this chronological interpretation. This article sets a foundation for the research strategies and technologies needed to identify archaeological targets at greater depth on the Australian continental shelf and elsewhere, building on the results presented. Emphasis is also placed on the need for legislation to better protect and manage underwater cultural heritage on the 2 million square kilometres of

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Recent studies conducted in Murujuga Sea Country have confirmed that Indigenous Australian archaeology does not end at the modern shore. Since the earliest peopling of the Australian continent, sea levels have fluctuated significantly, dropping as much as 130 m below modern mean sea-level during the Last Glacial Maximum (LGM). During this period, the continent (including Australia and New Guinea) represented a landmass one-third larger than present day Australia. As sea levels rose following the LGM, this extensive cultural landscape was inundated. The recent reporting of archaeological remains in a submerged context at Murujuga has enabled an integrated analysis of the archaeological landscape, based on direct evidence from archaeological sites that were originally formed on dry land, but are now located in intertidal and submerged environments. This study applies a landscape analysis centred on the submerged Cape Bruguieres channel site, and the Gidley Islands, where submerged, intertidal and coastal archaeology has been recorded. Aerial, pedestrian, and intertidal archaeological surveys were conducted to investigate the onshore and offshore landscape, providing new evidence with which to place the stone artefacts in the Cape Bruguieres channel into a wider context. Rock art engravings, grinding patches, quarries and upstanding stonessome of which are in the intertidal zonepoint to the use of a landscape that is now submerged and to the possibility of discovering new underwater sites. By integrating evidence from subtidal and intertidal contexts with the onshore record, we explore the cultural landscape above and below the 'waterline' as a continuum.

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