In a

keel The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. As the laying down of the keel is the initial step in the construction of a ship, in Br ...

boat, a death roll is the act of

broach The BROACH warhead is a Tandem-charge, multi-stage warhead developed by Team BROACH; BAE Systems Global Combat Systems Munitions, Thales Missile Electronics and QinetiQ. BROACH stands for ''Bomb Royal Ordnance Augmented CHarge''. Development of ...

ing to windward, putting the

spinnaker pole A spinnaker pole is a spar used in sailboats (both dinghys and yachts) to help support and control a variety of headsails, particularly the spinnaker. However, it is also used with other sails, such as genoas and jibs, when sailing downwind with ...

into the water and causing a crash-

jibe A jibe (US) or gybe (Britain) is a sailing maneuver whereby a sailing vessel reaching downwind turns its stern through the wind, which then exerts its force from the opposite side of the vessel. Because the mainsail boom can swing acros ...

of the

boom Boom may refer to: Objects * Boom (containment), a temporary floating barrier used to contain an oil spill * Boom (navigational barrier), an obstacle used to control or block marine navigation * Boom (sailing), a sailboat part * Boom (windsurfi ...

and

mainsail A mainsail is a sail rigged on the main mast of a sailing vessel. * On a square rigged vessel, it is the lowest and largest sail on the main mast. * On a fore-and-aft rigged vessel, it is the sail rigged aft of the main mast. The sail's foot ...

, which sweep across the deck and plunge down into the water. The death roll often results in the destruction of the spinnaker pole and sometimes even the

dismasting Dismasting, also spelled demasting, occurs to a sailing ship when one or more of the masts responsible for hoisting the sails that propel the vessel breaks. Dismasting usually occurs as the result of high winds during a storm acting upon masts, ...

of the boat. Serious injury to crew is possible due to the swift and uncontrolled action of the boom and associated gear sweeping across the boat and crashing to the (now) leeward side. For

dinghy A dinghy is a type of small boat, often carried or towed by a larger vessel for use as a tender. Utility dinghies are usually rowboats or have an outboard motor. Some are rigged for sailing but they differ from sailing dinghies, which ...

sailors, a death roll is a common type of oscillation while running downwind. It may, and often will, result in a

capsize Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is upside down in the water. The act of recovering a vessel fro ...

and even a full inversion if the skipper does not take quick action to prevent one. During a death roll, the boat ''rolls'' from side to side, becoming gradually more unstable until either it capsizes or the skipper reacts correctly to prevent it. While on the

dead run A point of sail is a sailing craft's direction of travel under sail in relation to the true wind direction over the surface. The principal points of sail roughly correspond to 45° segments of a circle, starting with 0° directly into the wind. ...

, off the wind, the force exerted by the sail lies almost parallel to the center line of the boat. There is little or no force causing the boat to heel to leeward, unlike most other points of sailing, and, if the sail is out past perpendicular to the center line, or the sail is incorrectly shaped, there may be a force causing the boat to heel to windward. Instabilities in the wind, and turbulence caused by the sail, which 'fouls' the wind on such a tack, may cause this force to change rapidly. Most sailors also retract the

centerboard A centreboard or centerboard (US) is a retractable hull appendage which pivots out of a slot in the hull of a sailboat, known as a ''centreboard trunk'' (UK) or ''centerboard case'' (US). The retractability allows the centreboard to be raised t ...

s of their dinghies while on the run, to reduce drag and increase speed. The lack of resistance to the rolling motion can enhance it. IOR (International Offshore Racing) boats in the 1970s and 1980s were known for death rolls due to their small mains that made them unbalanced downwind. Many boats put up spankers, big A-type sails set to leeward and flown away from the boat, to balance the boat. The higher the wind speed, the more important the spanker was to balance the boat.

Boats prone to death rolls

High-performance racing dinghies are most prone to death roll situations. These include skiff designs, such as the

Musto Skiff The Musto Skiff is a single-handed sailing skiff with a length of . It features a trapeze, asymmetrical spinnaker, wings and low weight and achieves speeds of over , which makes it one of the fastest single-handed sailing boats. History It was ...

, 29er, 49er and

International 14 The International 14 is a British racing sailboat, crewed by two sailors. The class was established in 1928. The boat is a developmental sailing class and so the design rules and the boats themselves have changed dramatically over time to keep ...

. Sailors of these boats generally prefer to sail on the

broad reach A point of sail is a sailing craft's direction of travel under sail in relation to the true wind direction over the surface. The principal points of sail roughly correspond to 45° segments of a circle, starting with 0° directly into the wind ...

rather than on the

because the boat is more stable and actually faster. Additionally, as their speed increases on the broad reach, their

apparent wind Apparent wind is the wind experienced by a moving object. Definition of apparent wind The ''apparent wind'' is the wind experienced by an observer in motion and is the relative velocity of the wind in relation to the observer. The ''velocity o ...

changes to allow them to point lower. Often they can point as low as the other boats, only faster. See ''

Sailing faster than the wind High-performance sailing is achieved with low forward surface resistance—encountered by catamarans, sailing hydrofoils, iceboats or land sailing craft—as the sailing craft obtains motive power with its sails or aerofoils at speeds that are ofte ...

''. More traditional racing dinghies such as the

Laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...

and

Laser Radial The Laser Radial or ILCA 6 is a popular one-design class of small sailing dinghy, originally built by Laser Performance. It is a singlehanded boat, meaning that it is sailed by one person. The Laser Radial is a variant of the Laser standard, ...

are also prone to death rolls. Singlehanders without

shrouds Shroud usually refers to an item, such as a cloth, that covers or protects some other object. The term is most often used in reference to '' burial sheets'', mound shroud, grave clothes, winding-cloths or winding-sheets, such as the famous S ...

will actually sail faster

downwind Windward () and leeward () are terms used to describe the direction of the wind. Windward is ''upwind'' from the point of reference, i.e. towards the direction from which the wind is coming; leeward is ''downwind'' from the point of reference ...

when sailing slightly "by the lee", or past dead downwind, where stability improves and death rolls are less likely.

References

{{DEFAULTSORT:Death Roll Sailing manoeuvres