Editing Hull (watercraft) (section)

===Planing and displacement hulls===
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[[File:Royal Navy MTB 5.jpg|thumb|[[Royal Navy]] World War II [[Motor Torpedo Boat|MTB]] planing at speed on calm water showing its [[Chine (boating)#Various types of chine hulls|hard chine hull]] with most of the forepart of the boat out of the water.]]
* Displacement hull: here the hull is supported exclusively or predominantly by [[buoyancy]]. Vessels that have this type of hull travel through the water at a limited rate that is defined by the waterline length except for especially narrow hulls such as sailing [[multihulls]] that are less limited this way.
* Planing hull: here, the [[Planing (boat)|planing]] hull form is configured to develop positive [[dynamic pressure]] so that its [[Draft (hull)|draft decreases]] with increasing speed. The dynamic lift reduces the wetted surface and therefore also the [[Drag (physics)|drag]]. Such hulls are sometimes flat-bottomed, sometimes V-bottomed and more rarely, round-bilged. The most common form is to have at least one chine, which makes for more efficient planing and can throw spray down. Planing hulls are more efficient at higher speeds<!-- Removed the suggestion that hull speed is a "maximum" speed which can't be overcome -- see [[Hull speed]] or <ref>{{cite web| url=http://www.boatdesign.net/forums/boat-design/hull-speed-1220.html| title=Hull speed}}</ref> for an explanation of this misconception -->, although they still require more energy to achieve these speeds. An effective planing hull must be as light as possible with flat surfaces that are consistent with good sea keeping. Sailboats that plane must also sail efficiently in displacement mode in light winds.
* Semi-displacement, or semi-planing: here the hull form is capable of developing a moderate amount of dynamic lift; however, most of the vessel's weight is still supported through buoyancy.