Coastal structures represent the most significant anthropogenic intervention in nearshore sediment dynamics, which impacts shoreline geometry and morphology. This study investigates the coupled response of shoreline position, orientation, and nearshore bathymetry to breakwater construction in Batemans Bay spanning over two centuries. For this, historical toposheets (1825-1922), containing bathymetric soundings surveys, were digitised and georeferenced to extract shoreline positions. These were complemented by aerial photographs, satellite imagery (e.g., Landsat and Sentinel-2), and hydrographic surveys from 1922 onwards to provide a continuous multi-temporal record of shoreline and bathymetric change. Comparative analyses were conducted between pre- and post-breakwater periods to identify spatial and temporal variations in shoreline dynamics. Change detection analysis highlights distinct phase shifts in shoreline behaviour associated with documented human intervention, reflecting modifications to natural processes, including wave energy distribution, tidal dynamics, sediment supply, and estuarine processes. Integrated shoreline and bathymetric analyses were used to map zones of erosion and accretion across the bay, revealing spatial patterns of sediment redistribution linked to breakwater construction and altered sediment transport pathways. The results also highlight the integrated three-dimensional coastal response and the potentially irreversible geomorphic impacts of breakwater construction, informing future coastal hazard assessment and adaptive management.