Which terms do hydrographers use in their communication? Which ones do they use particularly often? And which terms do exclusively exist because hydrography exists? With the methods of terminology science it is possible to systematically derive the terminology of hydrography. In this paper, I describe how terms can be collected and how concepts can be identified starting from the German language, how English equivalents can be assigned and how the terms can be made available in a terminology database. This paper is focused on describing the methodological approach, illustrated by selected examples. The methods could be transferred to other languages, but could also be used to update the IHO Hydrographic Dictionary, for example. First results suggest that the terminology of hydrography is not too extensive. In addition to the purely hydrography-exclusive terms, hydrographers also use numerous terms from other disciplines. However, hydrographers should at least know a few hundred concepts to be able to communicate competently. This paper also contributes to the debate on the term hydrospatial.