1. The science which has for its object the description of the waters of the earth’s surface, the sea, lakes, rivers, etc., comprising the study and mapping of their forms and physical features, of the contour of the sea-bottom, shallows, etc., and of winds, tides, currents, and the like. 2. The subject-matter of this science; the hydrographical features of the globe or part of it; the distribution of water on the earth’s surface.
3. The scientific description and analysis of the physical conditions, boundaries, flow, and related characteristics of the earth's surface waters.
4. The mapping of bodies of water.