FLUX, in Hydrography, a regular periodical motion of the sea, happening twice in twenty-four hours, in which the water is raised and driven violently against the shores. The flux or flow is one of the motions of the tide; the other, by which the water sinks and retires, is called the reflux or ebb. There is also a kind of rest or cessation of about half an hour between the flux and reflux, during which time the water is at its greatest height, and thence called high water. See TIDES.