Editing Hull (watercraft) (section)

====Chined and hard-chined hulls====
{{Further|Chine (boating)}}

A chined hull does not have a smooth rounded transition between bottom and sides. Instead, its contours are interrupted by sharp angles where predominantly longitudinal panels of the hull meet. The sharper the intersection (the more acute the angle), the "harder" the chine. More than one chine per side is possible.

The Cajun "pirogue" is an example of a craft with hard chines.

Benefits of this type of hull include potentially lower production cost and a (usually) fairly flat bottom, making the boat faster at [[Planing (sailing)|planing]]. A hard chined hull resists rolling (in smooth water) more than does a hull with rounded bilges (the chine creates turbulence and drag resisting the rolling motion, as it moves through the water, the rounded-bilge provides less flow resistance around the turn). In rough seas, this can make the boat roll more, as the motion drags first down, then up, on a chine: round-bilge boats are more seakindly in waves, as a result.

Chined hulls may have one of three shapes:
* Flat-bottom chined hulls
* Multi-chined hulls
* V-bottom chined hulls. Sometimes called hard chine.

Each of these chine hulls has its own unique characteristics and use. The flat-bottom hull has high initial stability but high drag. To counter the high drag, hull forms are narrow and sometimes severely tapered at bow and stern.{{citation needed|date=January 2022}} This leads to poor stability when heeled in a sailboat.{{citation needed|date=January 2022}} This is often countered by using heavy interior ballast on sailing versions. They are best suited to sheltered inshore waters. Early racing power boats were fine forward and flat aft. This produced maximum lift and a smooth, fast ride in flat water, but this hull form is easily unsettled in waves. The multi-chine hull approximates a curved hull form. It has less drag than a flat-bottom boat. Multi chines are more complex to build but produce a more seaworthy hull form. They are usually displacement hulls. V or arc-bottom chine boats have a V{{nbsp}}shape between 6°{{nbsp}}and 23°. This is called the {{nautical term|deadrise}} angle. The flatter shape of a 6-degree hull will plane with less wind or a lower-horsepower engine but will pound more in waves. The deep V{{nbsp}}form (between 18{{nbsp}}and 23{{nbsp}}degrees) is only suited to high-powered planing boats. They require more powerful engines to lift the boat onto the plane but give a faster, smoother ride in waves. Displacement chined hulls have more wetted surface area, hence more drag, than an equivalent round-hull form, for any given displacement.