So, what happens is you come across a model scale, you have to have a scale of the model, which is defined as length of ship divided by length of model, and generally this is represented by the Greek letter lambda. So, if I have got a 100 meter ship and we want to test a model of that, I may decide to go for a 2 meter model length, then the scale will be 50- then every model dimension is reduced by the same ratio. So, what happens to displacement model, displacement, how much should be the displacement? Displacement is reduced from the actual displacement of the ship by lambda cubed times because displacement is multiplication of three length dimensions. Similarly, weighted surface