hīˈdrägrəfē noun
( -es )
Etymology: Middle French hydrographie, from hydr- + -graphie -graphy (from Latin -graphia )
1. : the description and study of seas, lakes, rivers, and other waters: as
a. : the measurement of flow and investigation of the behavior of streams especially with reference to the control or utilization of their waters
b. : the measurement of tides and currents especially as an aid in navigation
c. : the surveying, sounding, and charting of bodies of water
2. : bodies of water or a representation of them on a map