Practical squat assessment for a ship manoeuvring in muddy environments

The condition of the bottom is practically never assessed in squat prediction formulae, but plays an important role in the magnitude of the squat prediction, as is shown in the present paper. Based on a comprehensive dataset of historical towing tank tests, a comprehensive 6 DOF manoeuvring model has been derived, which is used as a basis to derive a practical correction term which can be applied to common empirical squat prediction formulae to account for the presence of a muddy bottom. It seems that in normal sailing conditions, with small drift angles, a minor increase of the maximal sinkage prediction is needed when it is not desired to touch the mud layer with the ship