Jibe

From Wikipedia, the free encyclopedia

This article is about the sailing maneuver. The term has other definitions.

A jibe or gybe is when a sailing boat (yacht) turns its stern through the wind, such that the direction of the wind changes from one side of the boat to the other. The term wearing ship is used in tall ships for jibing.

The opposite of a jibe is a tack which is turning the bow of the boat through the wind.

1 Spelling
2 Use of jibing
3 Dangers inherent in jibing
4 Alternatives to jibing
5 See also

[edit] Spelling

While jibe and gybe are both acceptable spellings of the term, gybe is the more common spelling in British English, while jibe is the more common spelling in American English.

[edit] Use of jibing

Jibing is a less common technique than tacking, as a sailboat can sail straight downwind, whereas they generally cannot sail straight into the wind (only indirect systems, such as those using a windmill geared to a propellor, are able to sail straight into the wind). However, many sailboats are significantly faster sailing on a broad reach than running (sailing straight downwind), so the increased speed of a zig-zag course of alternating broad reaches can make up for the extra distance it takes over a straight downwind course. The sailboat will execute a jibe manueuver when it changes course as it zig-zags downwind. Jibing is also used commonly in races, which often use a triangular course marked with buoys; the most direct way of rounding a buoy may be to jibe. A jibe can generally be completed more quickly than a tack because the boat never turns into the wind, and thus a jibing boat's sails are always powered where a tacking boat's sails are unpowered as the bow crosses through the wind.

When running, one may use a jibe to place the mainsail on the opposite side of the boat from the foresail. This keeps both sails exposed to the wind, and allows wind to spill from the mainsail to the foresail, resulting in more efficient use of wind. This technique is sometimes referred to as running "goose-winged", "gull-winged", or "wing and wing". When running wing and wing, a spinnaker pole or whisker pole is often used to hold the clew of the foresail out to the windward side of the boat.

[edit] Dangers inherent in jibing

A jibe can be a dangerous operation in a fore-and-aft rigged boat because, as the boat's stern turns through the eye of the wind, the "old" leeward side of the mainsail and boom suddenly becomes the new windward side. Load on the sail and mainsheet rise quickly in proportion to the change in projected sail area and if uncontrolled, the boom and mainsail can swing across the deck with great force, injuring anyone standing in the path of the boom, the mainsheet or its tackle as they sweep across the boat. An uncontrolled boom slamming to the limit of its range may also put excessive stress on the rigging, and can break the boom or standing rigging, perhaps even bringing the mast down. A jibe can also result in a sudden change in the direction of heeling, which can cause unwary passengers or crew to lose their balance or even go overboard.

To reduce the dangers of jibing on a small boat, the boom is often guided across the boat by hand as the stern of the boat crosses through the eye of the wind, then is eased out to its new sailing position. On a larger boat the mainsheet is tightened during the turn to limit the range of movement of the boom (see preventer). Once on the new course the mainsheet is released and the mainsail trimmed. These techniques prevent the boom from swinging unexpectedly. Accidental jibes may occur when sailing on a course that is running dead downwind if the wind catches the leeward side of the sail. See broach, Chinese gybe, death roll.

When sailing dinghies in high winds, a boat can capsize shortly after a jibe due to helmsman error (loss of tiller control) or tripping over the centerboard. It is partly for this second reason that centerboards are often lifted while sailing downwind even in non-planing hulls.

[edit] Alternatives to jibing

The term chicken jibe refers to the process of turning upwind and tacking through more than 180 degrees to avoid having to jibe on a downwind course. While much slower, this technique avoids the dangers of passing the boom across the boat under load.