Flare (ship)

{{Short description|Design element of ships}}

{{For|the maritime distress signal|Flare#Maritime distress signal}}

File:USS_Wisconsin.jpg from below, exposing the flares.]]

Flare is the angle at which a ship's hull plate or planking departs from the vertical in an outward direction with increasing height. A flared hull typically has a deck area larger than its cross-sectional area at the waterline. Most vessels have some degree of flare above the waterline, which is especially true for sea-going ships. Advantages of hull flare can include improvements in stability, splash and wash suppression, and dockside utility.{{cite web | title=Dynamic Stability of Flared and Tumblehome Hull Forms in Waves; Basler, C. &c. | url=http://www.dept.aoe.vt.edu/~mccue/papers_archive/bassler_etal_stab07.pdf | access-date=2011-05-21 | archive-date=2017-07-07 | archive-url=https://web.archive.org/web/20170707225531/http://www.dept.aoe.vt.edu/~mccue/papers_archive/bassler_etal_stab07.pdf | url-status=dead }} Flare can also induce instability when it raises the center of gravity and lateral torque moment of a vessel too much (by negatively impacting its righting moment and metacentric height).

Tumblehome is the inverse of flare, where the hull becomes narrower with increasing height.