Water line : Any one of certain lines of a vessel, model, or plan, parallel with the surface of the water at various heights from the keel.

Water line : Any one of several lines marked upon the outside of a vessel, corresponding with the surface of the water when she is afloat on an even keel. The lowest line indicates the vessel's proper submergence when not loaded, and is called the light water line; the highest, called the load water line, indicates her proper submergence when loaded.

Example:


Taxonomy
load line, Fresh Water, waterline, draft, vessel, Tropical Timber, summer load, Seawater, line marks, Regulations, Subdivision, the Load, North Atlantic, the Summer, waterline length, Passenger vessel, Merchant Shipping, Load Line Mark.

Defination from the web:
Water load line is an amount equal to centimetres above the summer load line where is the displacement in metric tonnes at the summer ... In any case where cannot be ascertained the fresh water load line is at the same level as the tropical load line. ...