The action when wearing a sailing vessel at the moment when the boom of the mainsail swings across as the wind crosses the stern. The word can also be used as a noun, e.g. a ship can make a gybe.
The stronger the wind, and the greater the area of the mainsail and weight of the main boom, the more strain a gybe will put on gear and crew, but if properly sailed a fore-and-aft-rigged vessel should be able to gybe in any strength of wind in which it can carry normal sail. The force of the gybe is broken by hauling in the main sheet before the boom is allowed to swing across, thus considerably reducing the strain as the gybe takes place. If the wind is so strong that a gybe would be dangerous, this may be a reason for setting a trysail. An involuntary gybe, caused by running by the lee through bad steering, or by a sudden squall from an unexpected quarter, is always dangerous.
If the vessel is not fitted with a permanent backstay, the operation of gybing requires the setting up of the weather runner (when the vessel is on its new tack) before the boom swings across the stern, and the overhauling of the lee runner to allow the boom to swing forward as the wind takes it. To gybe without attending the runners, or to do so involuntarily, is known as to gybe all standing, and is dangerous as it could dismast the vessel.
Subjects: Maritime History.