This dataset contains acceleration data for seven 'Mini Buoys' (low-cost open-source bottom-mounted float sensors for measuring inundation duration, current velocity, and wave orbital velocity from acceleration data) and local water levels used in a pilot study to determine the effect of weight and tether length on the sensitivity of the B4+ Mini Buoy to detecting hydrodynamics. Additional datasets provided are used for deriving near-bottom wave orbital velocities using two methods: linear wave theory and direct velocity measurements. Both methods were then used to compare calibrations between velocity and acceleration data gathered by low-cost and open-source bottom-mounted floats called 'Mini Buoys'. The dataset contains water velocity data gathered by Acoustic Doppler Velocimeters, and acceleration data gathered from the B4+ Mini Buoy design. Furthermore, a dataset is provided for Mini Buoy calibration, which uses the drag-tilt principle to infer hydrodynamics from acceleration data. The dataset contains acceleration data gathered from three 'Mini Buoy' designs ('B4', 'B4+', and 'Pendant'), alongside water level, current velocity, and wave orbital velocity measured from a range of commercially-available sensors, in order to build calibration curves for inferring hydrodynamics from acceleration data. Full details about this dataset can be found at https://doi.org/10.5285/bdd3b831-0f66-4593-a141-dee0784145e1