the part of the outside of a ship's hull that is just at the water level
2. Naval Architecture.
any of a series of lines on the hull plans of a vessel representing the level to which
the vessel is immersed or the bottom of the keel. Compare load line
, Plimsoll line
in which water at its surface borders upon a floating body.
5. Also called watermark.
a line indicating the former level or passage of water: A water line all around the cellar served as a reminder of the flood.
a pipe, hose, tube, or other line for conveying water.