Hawaiʻi’s coastlines are complex and important systems affected by waves, terrestrial inputs, and sea level rise. As significant socioeconomic, scientific, and cultural spaces, it is critical to understand how these zones change over time and in the face of climate change. This project both monitors and models how Hawaiʻi’s beaches have changed since the early twentieth century. The team monitors beaches using high resolution GNSS surveying, airborne and drone imagery, and satellite shoreline detection. Using this data, the team creates robust process-based models (CoSMoS-COASTS) that can predict future shoreline positions and coastal erosion hazard zones. These modeled results and accompanying imagery are used by policymakers and planners to inform setback laws and climate adaptation strategies.