Sea level rise poses existential threats to shoreline ecosystems and infrastructure. Ocean elevations constantly change due to thermal expansion, storms, precipitation runoff, tides, and waves. Shoreline ecosystems and infrastructure are adapted to a range of historical conditions. If the sources and degree of elevation change, then conditions may evolve beyond current adaptations and resilience. We describe a method to measure very fine-scale (spatial and temporal) changes in water elevations and shoreline geomorphology and conditions. In 2016, 35 time-lapse cameras were placed alongside infrastructure and shoreline marshes and beaches in California’s San Francisco Bay area and Georgia’s barrier island (Jekyll Island). We will present lessons from 5 years of applying this approach to multi-scale monitoring of shoreline positions and conditions. Between 2016 and 2021, we identified several major changes in shoreline conditions that pose a risk in the short-term to adjacent infrastructure: 1) rapid in-shore migration of a beach on Jekyll Island transforming a tidal marsh to an extension of the beach; 2) increase in CA tidal marsh inundation (as % flooded area), which could result in change in marsh composition from low-mid marsh to mudflat; and 3) change in shoreline vegetative cover from generally vegetated to less vegetated. Along the beach on Jekyll Island, maritime forest was lost and became beach and within marshes in CA, mid-marsh areas became and are continuing to become mudflats). In California, these results are consistent with findings by CA author Shilling of decadal-scale: 1) re-distribution of tidal marsh sediment using fine-scale ground surface elevation measurements; and 2) loss of marsh vegetation using satellite imagery. In Georgia, the mechanism for rapid change seemed to be a combination of an unprecedented increase in frequency of tropical cyclones and gradual changes. Changes observed on-shore are consistent with near-shore sediment conditions. Shipping channel deepening potentially removes near-shore sediment that could limit onshore adaptation by shoreline ecosystems. In California, there was no obvious change in response to stochastic storm events and instead we observed a gradual change in shoreline flooding and vegetation, which may have been exacerbated by in-shore highways and levees. The transformations did not reflect new mechanisms of shoreline change, but may reflect an acceleration of changes beyond adaptive capacity of shoreline ecosystems, resulting in state changes. Transformation of vegetated marsh into mudflats (CA) or beach (GA) could increase the rate of shoreline loss, threatening any infrastructure along the >120,000 km of US and 1.6 million km of global shorelines. The fact that we were able to measure changes over such short time periods (years), consistent with projections from climate change studies was quite surprising to us, but highlighted the need for fine-scale shoreline tracking systems.