High-resolution field acceleration measurements of a slack-moored buoy in a tidal estuary with a view to wave-energy applications

Abstract

A high-resolution field dataset of acceleration measurements from a slack-moored beacon buoy deployed in the Bahía Blanca estuary (Argentina) is presented. This study is motivated by the potential integration of wave-energy conversion devices on existing navigation buoy platforms, with particular attention to pendulum-based energy harvesters. The campaign spanned three continuous weeks, yielding over 18 million tri-axial acceleration samples at 10 Hz. The buoy response was interpreted by jointly considering the acceleration records, tidal predictions, and wind data from the Oceanographic Tower, located approximately 20 km from the measurement site. These external data were used as contextual information to identify broad environmental forcing regimes. The analysis reveals persistent dynamical features, including a low-frequency surge-pitch response consistently observed between 0.23–0.26 Hz and a wave-frequency band near 0.45 Hz. Intermittent amplified acceleration events are identified and interpreted as the possible combined effect of wave packets, wind–current interaction, and mooring-controlled dynamics. The spectral structure remains remarkably stable across the analyzed conditions, suggesting that the dominant buoy motions are governed by robust estuarine forcing and the intrinsic dynamics of the buoy-mooring system. Finally, a simplified pendulum-based energy-harvesting model is used to connect the measured acceleration levels with the expected order of magnitude of extractable power, showing the potential relevance of the dataset for preliminary wave-energy feasibility studies. To the authors’ knowledge, this is the first long-duration, high-frequency acceleration dataset for a moored buoy in a South Atlantic estuary. The dataset is publicly available to support model validation, benchmarking, and coastal and wave-energy engineering studies.