When a tsunami attacks a port, fishing boats are often carried away by the strong current. Not only the direct damage in fishery but also the indirect damage may occur, e.g. the fishing boat destroys a building or a coastal structure. Therefore, it is desirable to moor fishing boats by strong mooring rope or to let them evacuate from the port. The experimental study is presented on the behavior of fishing boat moored at quaywall and the tension in mooring rope. The equation that evaluates the required diameter of mooring rope based on the Young's modulus and the length of mooring rope, the mass of boat, the current velocity and so on is proposed through the experimental results. Based on this equation, the required diameter of mooring rope could be determined.
