Waterline

The water line, the line resulting from the intersection of the water surface with the hull of a floating vessel. Since it varies with the loading of the ship, is defined with an assumed weight of the yard a design waterline ( KWL).

The length of the waterline is determinative of the hull speed, so the theoretical maximum speed of the boat in the displacement mode. An old maritime rule of thumb is this: length runs. Approximate way, the maximum speed in knots calculated by the following formula from the length of the waterline in meters:

To overcome this speed, a considerable amount of energy must be expended. However, the speed is overcome, the vessel passes into the so-called planing, in which the body surface which contacts the water is low, and thus the frictional resistance decreases in the water. However, not every water vehicle can pass onto the plane. It is primarily dependent on the hull shape.