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 from one corner of the sail to the other. In a dinghy it is sometimes necessary to raise the centerboard to prevent the boat from capsizing during this somewhat violent maneuver.
Because of the dangers in jibing, warning the crew is important. The phrase "standby to jibe" is usually used to let a prepared crew take necessary action. The phrase "jibe ho" is the common phrase when the helmsman actually applies rudder action to change direction.
When running (sailing nearly directly downwind), one may jibe 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.
To reduce the dangers of jibing on a small boat, the boom is often sheeted in and guided across the boat by hand as the direction of the wind crosses the centerline of the boat, and then the mainsail is eased out to its new sailing position. On a larger boat the mainsheet is also tightened during the turn to limit the range of movement of the boom (see preventer). When jibing it is usually safer to sail nearly directly downwind briefly before and after the jibe and make a small boat direction change when jibing, so that there less heeling force on the boat during a jibe. Then you can continue a course change to higher points of sail(broad or beam reach)after the jibe is complete and crew relocated. Once on the new course the mainsheet is eased and/or trimmed mainsail. 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. When the wind direction crosses the centerline of the boat, and a jibe is not executed, the point of sail is referred to as "by the lee" When sailing "by the lee" the outer edge of the mainsail is facing slightly into the wind. Slight changes in the boat heading, rolling motion, or wind direction can cause an unexpected and surprising jibe, suddenly and forcefully flipping the mainsail to the opposite side of the boat. Do not sail "by the lee" except for brief durations (such as to avoid an obstacle), and only when keeping the crew clear of the boom swing and the arc of the mainsheet sweep. 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. The main reason being that a centreboard/keel is not needed for sailing downwind and simply adds to the drag of the hull. Raising the centre-board reduces drag and increases the boat's speed.