Raw acceleration data and images are provided for 20 locations spaced at ~500 m on the mudflat ~2 m in front of eroding or expanding edges of Caerlaverock saltmarsh, Solway Firth, Scotland. Acceleration data was gathered by the Mini Buoy (B4+ design) at rates of either 1 second (monthly redeployments) or 10 seconds (quarterly redeployments) between March 2021-2022. The data has been cleaned to remove any data gathered before/after deployment. Coordinates of each location and the status of the marsh edge (eroding or expanding), and images of the marsh edge at each Mini Buoy deployment are also present. The data is being used to identify hydrological thresholds (inundation duration, current and wave orbital velocities) that determine whether saltmarshes expand or erode. Full details about this dataset can be found at https://doi.org/10.5285/3845e060-2a43-4b7e-845a-726f54a4867d