New definition of the nautical bottom in muddy areas

Themes: Water & Maritime, Infrastructure & Mobility / Transport

Proof of principle

A TRL is a measure to indicate the matureness of a developing technology. When an innovative idea is discovered it is often not directly suitable for application. Usually such novel idea is subjected to further experimentation, testing and prototyping before it can be implemented. The image below shows how to read TRL’s to categorise the innovative ideas.

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By developing a more accurate and reliable definition of the nautical bottom, uncertainties in the Under Keel Clearance estimation can be reduced; ensuring safety, minimising the need for dredging, and possibly increasing port capacity.


Current nautical bottom definitions are based on fluid mud’s density, while it is known that this has no conclusive relation with the safety of sailing through this mud. The new definition will be based on rheology of the mud.


A first pilot to compare rheological and density measurements of mud has been completed. These results are a first step towards a new definition of the nautical bottom.

Alex Kirichek


Prof. Tiedo Vellinga

Dr. Claire Chassagne

Prof. dr. Han Winterwerp

Arie Noordijk