This paper provides a new insight into the surveying strategies that are used (or can be potentially used) in ports and waterways with fluid mud layers. The combination of acoustic methods with other methods, which are based on the density or on the shear strength measurements, is discussed. In particular, the measurements by the DensX, the Rheotune, the Graviprobe and the Rheocable are presented Due to the complexity of mud, the strength of mud exhibits a non-linear relationship with the density due to the thixotropic behaviour (deformation, history and time dependence). Therefore, sampling and measuring procedures, followed by data processing and interpretation of the measurements, have to be standardized by means of recognized practical protocols. In-situ measuring tools are available for characterizing the behaviour of fluid mud. Based on our observations, we can conclude that the new surveying strategies can be potentially developed in the ports and waterways with fluid mud layers.@en