Refraction—Diffraction of Irregular Waves over a Mound

The transformation of monochromatic and directionally‐spread irregular waves passing over a submerged elliptical mound was studied in a controlled laboratory experiment. A directional spectral wave generator was used to generate waves with equal peak frequencies and spectral energy, along with monochromatic waves of equivalent significant height and period. Spectra with both narrow and broad frequency and directional spreads were generated. Results indicate that monochromatic waves provide a poor approximation of irregular wave conditions if there is directional spread or high wave steepness.