This dataset supports the experimental study on the hydrodynamic behavior of vertical cylinders representative of structural elements of Offshore Floating Photovoltaic (OFPV) platforms under both wave and steady-current conditions. The experiments were conducted in a 25 m wave flume at the Energy Engineering Department (Bilbao School of Engineering, UPV/EHU). The work aims to determine reliable hydrodynamic coefficients for Morison-type formulations and to analyze wake effects between cylinders arranged at different spacings. The results show consistent trends in inertia and drag coefficients across a wide range of Keulegan–Carpenter (KC) numbers, as well as notable differences between wake recovery under waves—where flow recovers rapidly—and steady currents, where wakes are stronger and significantly influence downstream forces. The dataset is organized into two main directories corresponding to the experimental campaigns: Currents and Waves. Each directory includes:– A main MATLAB script for data analysis and a second script for post-processing and plotting.– A Functions folder containing all supporting MATLAB functions.– A Raw data folder, with files named according to cylinder diameter, draught, flow velocity, cylinder spacing, and test number (e.g., D50d50U0.4L37.5P1). In the wave experiments, raw data are further split by diameter, with subfolders for each spacing (Lxxx) and corresponding force and wave elevation measurements.– A Results folder containing processed numerical outputs (Excel files) and all generated plots. This structure ensures full reproducibility of the hydrodynamic coefficient calculations and wake-interaction analyses.