The potential of long ship-induced waves to serve as a physical model for tsunami waves (called simply tsunami below) is examined. Such waves (wavelengths more than 200 m at depths down to 10–20 m) are induced by high-speed ferries sailing at near-critical speeds in semisheltered, relatively shallow areas. It is shown based on experience from Tallinn Bay, Baltic Sea, that for many aspects these waves can model nearshore dynamics and runup of tsunami caused by landslides, including processes of wave refraction, diffraction, and sea-bottom interaction in bays and harbors. Many governing nondimensional parameters (such as the nonlinearity, dispersion, Reynolds and Ursell numbers, surf similarity parameter, breaking parameter, etc.) of the largest ship waves and landslide tsunamis have the same order of magnitude. It is especially important that use of ship waves for wave propagation and runup studies allows their spatial structure to be accounted for adequately. Near-critical ship waves can therefore be used as a natural substitute for tsunami, for study under controlled and safe conditions.