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A jibe (US) or gybe (Britain) is a sailing maneuver whereby a sailing vessel reaching downwind turns its stern through the wind, such that the wind direction changes from one side of the boat to the other. For square-rigged ships, this maneuver is called wearing ship. In this maneuver, the mainsail will cross the center of the boat while the jib is pulled to the other side of the boat. If the spinnaker is up, the pole will have to be manually moved to the other side, to remain opposite the mainsail. In a dinghy, raising the centerboard can increase the risk of capsizing during what can be a somewhat violent maneuver, although the opposite is true of a dinghy with a flat, planing hull profile: raising the centerboard reduces heeling moment during the manouevre and so reduces the risk of capsize. The other way to change the side of the boat that faces the wind is turning the bow of the boat into, and then through, the direction of the wind. This operation is known as tacking or coming about. Tacking more than 180° to avoid a jibe is sometimes referred to as a 'chicken jibe'. == Use == Many sailboats are significantly faster sailing on a broad reach than running (sailing straight downwind). Thus the increased speed of a zig-zag course of alternating broad reaches can more than make up for the extra distance it takes over a straight downwind course. Jibing is also common in racing, which often use a triangular course marked with buoys; the most direct way of rounding a buoy may be to jibe. Jibing is a less common technique than tacking, since a sailboat can sail straight downwind, whereas it cannot sail directly into the wind and has to sail a zig-zag course at alternating angles into the wind. However, 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 whereas a tacking boat's luffing sails are un-powered while the bow crosses through or ''into'' the direction of the wind. 'Wearing ship' is the alternative maneuver for a square rigged ship that wishes to avoid the difficulties and hazards of tacking. Light winds, heavy seas, worn-out gear, and poor vessel or crew performance are all reasons a ship may choose to wear instead of tack. Compared to boats with a fore-and-aft rig, a square rigger can jibe without any difficulty or risk of accident. However, because since these craft cannot point close to the wind, they may find it difficult to maintain turning and forward momentum as the bow passes through the large No-go zone. If the ship loses steering way, it can be 'taken aback,' with the wind pressing on the forward surface of the sails and caught in irons. By driving the vessel backwards through the water, this puts excessive strain on the ship's masts, spars and rigging, could break the rudder, and in severe weather could dismast the ship. In some situations it was considered quicker and safer to take a square rigged ship to windward by executing a series of jibes, turning the vessel across the wind through 270 degrees rather than the 90 degrees of a tack. This, however, would result in considerable ground lost to leeward with each jibe. When running (sailing nearly directly downwind) in a sloop, one may 'jibe' only the mainsail to the opposite side of the boat. This keeps both the main and jib exposed to the wind resulting in a more efficient use of wind. Setting the mainsail and the jib on opposite sides of the boat is often referred to as running "goose-winged", "gull-winged", or "wing-and-wing". When running wing-and-wing, a light spinnaker pole or whisker pole is often used to hold the clew of the foresail out to the windward side of the boat. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Jibe」の詳細全文を読む スポンサード リンク
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