Ship manoeuvring behaviour in muddy navigation areas : state of the art

The manoeuvring behaviour of vessels is highly affected by their small under keel clearance in access channels and harbours. If sedimentation and the formation of mud layers occur in these areas the manoeuvring behaviour becomes even more challenged, especially because the exact location of the bottom is not unequivocally determined. In such areas the nautical bottom definition, as stated by PIANC, is useful: The nautical bottom is the level where physical characteristics of the bottom reach a critical limit beyond which contact with a ship’s keel causes either damage or unacceptable effects on controllability and manoeuvrability. Over the past decades research has been focussing on both the determination of the physical characteristics of the mud and the manoeuvring behaviour in such areas. The paper tends to give an overview of this research and of practical applications in harbours worldwide, and to provide an outlook for future research.