Abstract
When tsunami attacks in harbors, vessels moored at a wharf may be unable to evacuate. Vessels should prepare for the break of mooring tethers, grounding on a wharf, drift to land areas and the collision with buildings. The present paper describes the tsunami simulation and the motion analysis of moored vessels at a wharf. The chart of the break of mooring tethers was created. The chart shows the relation of wave height and the break of mooring tethers. And the influence of the install more mooring tethers to the break of mooring tethers was considered.