Abstract
Due to an increasing trend of replacing traditional paper navigational charts with electronic ones, requirements for the creation of new ENC have been steadily growing. One example is the precise electronic navigational chart, which is based on accurate mapping of topographic and hydrographic elements. Information about depth of the waters contained on the charts are crucial for the safety of navigation. During the production of precise navigational charts, bathymetric information acquired by a multi-beam sonar system (or swath-bathymetry interferometric system) is used. A multi-beam sonar system emits several signal beams from a single transducer in different directions, which allows to cover a hundred percent of the survey area. The authors of the article carried out an analysis of bathymetric data in terms of differences in their preparation for the production of precise ENC.