Marine lifting surfaces may undergo flow-induced vibrations due to fluid sources of excitation, leading to shorter life cycles due to structural fatigue and critical to the acoustic performances (e.g hydrofoil singing). As such, accurate understanding of the fluid-structure response of marine structures, as well as vibrations control and damping, are critical to many maritime applications. In particular, this work investigates the potential of the electromechanical coupling inherent to piezoelectric materials for passive vibration damping of a cantilever blunt flat plate under hydrodynamic flows. A prototype equipped with piezoelectric ceramics connected to an inductor, in order to act as a resonant piezoelectric shunt, is specifically designed for this study. Its flow-induced vibrations are first assessed within the water tunnel of IRENav to identify the natural frequency of interest to control. It shows that the plate is subjected to von Kármán vortex-shedding with two configurations, namely lock-off for the first-bending mode, and lock-in with the first torsional mode. The latter results in the most extreme vibration cases but is also the most difficult to control. Therefore, the first-bending mode is selected for this first experimental assessment. Second, semi-passive control strategies, using the resonant piezoelectric shunt, have been tested on the targeted natural frequency both in air and in still water. Subsequent comparisons show similar coupling factors, meaning that the performances of the resonant shunt should also be similar in air and in still water. Moreover, a numerical model, based on fluid-structure-piezoelectricity coupling, is also set-up to compute the coupling factors. Hence, a valuable numerical tool is provided for future designs of more complex geometries. Finally, experimental vibration mitigation is achieved both for still water and under hydrodynamic flows, experimentally proving the feasibility and relevance of this control solution for maritime applications.