Remotely Piloted Aerial System Applications for Maritime Archaeology Using the ‘Coastal Integration Workflow’: Case Studies from South-Eastern South Australia

Maritime archaeological survey within dynamic coastal environments presents significant challenges for Structure from Motion (SfM) photogrammetry due to wave motion, sun-glint, variable turbidity, and unstable sea-surface texture. This study develops and evaluates a Remotely Piloted Aircraft System (RPAS)-based survey methodology, termed the Coastal Integration Workflow (CIW), designed to improve photogrammetric reconstruction continuity and submerged landscape visualisation across nearshore maritime environments using consumer-grade drone platforms. The workflow was tested between 2021 and 2023 across multiple maritime archaeological case studies along the south-eastern South Australian coastline, including the Admella Wreck Project. This study examined how survey design parameters, including overlap configuration, waypoint orientation, terrestrial image anchoring, and autonomous flight planning, influenced reconstruction stability and orthomosaic quality across complex coastal environments. The case studies demonstrated the feasibility of combining increased image overlap, perpendicular offshore transects, and supplementary terrestrial coverage to support photogrammetric reconstruction and visualisation of shallow reef structures, seafloor morphology, and potential submerged archaeological material. While the surveys primarily relied on onboard GNSS positioning rather than formal GCP-controlled workflows, the CIW demonstrated strong potential as a cost-effective methodology for high-resolution coastal archaeological prospection, monitoring, and survey planning within dynamic maritime environments.