The presence of suspended sediments in water bodies presents significant challenges for the dredging industry. Existing methods to determine nautical depths are intrusive single point methods relying on in situ density or shear strength measurements or low-frequency single-beam echo sounder recordings. The use of single-beam echo sounders is however systemically problematic as they are not practical in satisfying the CATZOC A1 coverages required for contemporary electronic navigational charting.

Here the author describes a method to obtain ZOC category A1 for areas exhibiting suspended mud using multibeam echo sounders operating at an ultra-wide frequency range of 80–400kHz. This method reaches the nautical bottom as well as single-beam systems and generates high-resolution full search bathymetric maps.