So, what happen? If damping is depending on frequency; obviously, added mass is also depending on frequency because added mass and damping are two part of the same force. So, what happens in free surface phenomena radiation force, which is added mass and damping, becomes frequency dependant, in this also; that means, in what it means is that a z is a z omega; b z is b z omega. There is nothing like, there is the statement that added mass of this ship is so and so, is incorrect statement as for as heave or modes of motions are concerned, you have to tell at what frequency. Normally what has happen? You see I told you that at high frequency it is making ripple, practically no energy.