1. The document discusses best practices for managing navigational depth in the ports of Rotterdam, including through dredging, density surveying, and research on siltation. 2. It addresses port environment factors like tides, currents, and storms that can impact siltation. It also discusses different dredging management approaches and equipment used. 3. Density surveying techniques are outlined to map fluid mud layers and calculate navigational depth levels, including the use of echosounders, density probes, and sampling tools. Research on forces affecting siltation like currents, rivers, winds, and temperature is also summarized.