After the 2011 Great east Japan earthquake disaster, many reports on the tsunami profile at ports and disaster surveys on vessels moored in ports along the Pacific Ocean have been published. We also conducted surveys on the sea disasters of several large vessels such as crude oil and coal carriers by reproducing the moored vessel's behavior through a numerical simulation method on ship motions and tsunami. In a judgement of ship refuge action from ports, it is important for ship onboard and fleet management to grasp tsunami information after huge earthquake. In this paper, we have tried to find out a threshold of tsunami wave height for ship-mooring based on surveys on the observed tsunami data and the ship status in the ports during the 2011 Tohoku earthquake tsunami.
