Wa′ter-lines.
1. (Shipbuilding.) Ship's lines drawn parallel with the surface of the water, at varying hights. In the sheer plan they are straight and horizontal; in the half-breadth plan they show the form of the ship at the successive hights marked by the water-lines in the sheer plan.
2. (Nautical.) The line up to which the hull of a vessel is submerged in the water. Load water-line: the line to which a ship sinks with all her cargo and stores on board.