Near-surface aerosol fluxes over open water are critical for understanding air–sea interactions and atmospheric radiative budgets, yet direct micrometeorological observations remain very limited. To address this gap, this study presents the first application of a large-aperture scintillometer (LAS) for retrieving aerosol mass fluxes over open-water environments, including an inland lake and a coastal bay. LAS-derived fluxes were compared with conventional eddy-covariance (EC) measurements and independent dry-deposition calculations. Under conditions without severe optical attenuation, the LAS-derived fluxes exhibited temporal variations broadly consistent with EC measurements, with normalized root-mean-square errors (NRMSEs) to 15.0%–16.8%. The coastal campaigns revealed the operational boundary of this optical approach: dense fog and persistent high humidity severely attenuated the LAS signal and caused extended data gaps. Comparisons with dry-deposition calculations further showed that the path-averaged LAS measurements may better capture site-scale variability at the coastal site. Overall, these results demonstrate the potential of LAS as a valuable complements to traditional point measurements for characterizing aerosol exchange over open water.