The controlled gybe
1The lesson in plain words
A gybe turns the stern through the wind. Control the boom's crossing, warn the crew and keep heads low.
What a gybe is
Gybing (American English: jibing) changes tack by turning the stern, the back of the boat, through the wind. The mainsail can remain loaded as the stern crosses the wind, so an uncontrolled boom can swing violently. A controlled gybe brings the boom across under your control, at the moment you choose. The headsail may collapse or be blanketed, sheltered from the wind by the main.
Before you start
Check the new course is clear. Make sure everyone knows where the boom will swing and keeps their head below it. Check the mainsheet, the rope controlling the boom, is clear and runs freely. Check the kicker (vang), the line holding the boom down, is on; without it the boom lifts and the top of the sail can flip unpredictably.
Commands
Call "Stand by to gybe" (US: "Prepare to jibe") and wait for "Ready". Keep everyone clear of the boom and mainsheet. Bear away towards a run, with the wind nearly astern, then sheet the main to the centreline. A shorter mainsheet limits the boom’s swing and shock. Call "Gybe-oh" (US: "Jibe-ho") as you turn through dead downwind.
Through the gybe
Continue the turn gently through dead downwind. When the wind reaches the other side, the boom crosses. Let the mainsheet out smoothly but quickly on the new side, without letting it run free, and meet the turn, using opposite rudder to stop the swing. The boat can otherwise round up, swinging towards the wind and heeling hard. Finally bring the headsail across and trim for the new course.
Strong winds
In strong winds, consider tacking round instead of gybing, if you have enough clear water. Turn towards the wind, tack, then bear away onto the new course. This is sometimes called a chicken gybe. It needs sea room and a boat that can safely turn upwind. If you must gybe, keep speed up so the apparent wind, the wind you feel aboard, is lowest as the main crosses.
2Step by step
Controlled gybe on a yacht
- 1
Check the new course is clear, the kicker is on and the mainsheet runs free.
A loose kicker lets the boom lift; a tangled sheet stops control.
- 2
Call "Stand by to gybe"; wait for "Ready"; heads below the boom.
The boom can swing across the whole cockpit.
- 3
Bear away to a run and pull the mainsail into the centreline.
A short sheet gives the boom a short, gentle swing.
- 4
Call "Gybe-oh" and steer slowly until the boom crosses.
A slow turn keeps the moment of crossing under control.
- 5
Ease the mainsheet smoothly on the new side and meet with opposite helm.
Easing and counter-steering stop the boat rounding up.
- 6
Bring the headsail across, then trim both sails for the new course.
The boat settles on the new gybe with both sails working.
3Key data
- Commands (UK/RYA)
- "Stand by to gybe" – "Ready" – "Gybe-oh"
- Commands (US)
- "Prepare to jibe" – "Ready" – "Jibe-ho"
- Before the gybe
- Kicker on, mainsheet centred, heads low
- Strong winds
- Tack round if there is room and you can safely turn upwind
4Key points
- 1
A gybe turns the stern through the wind; the boom swings fully across.
- 2
Call "Stand by to gybe"; keep crew clear of boom and mainsheet and wait for "Ready" before centring the main.
- 3
Keep the kicker on and heads low; centre the main, then call "Gybe-oh".
- 4
After the boom crosses, ease the sheet and meet with opposite helm.
- 5
In strong winds, tack round if you have sea room and can safely turn upwind.
5Frequent mistakes
Wrong: Let the mainsheet run out as the boom crosses.
Right: Ease it under control. A free-running boom can hit the shrouds, the wires supporting the mast, and hurt crew or break gear.
Wrong: Gybing is just a tack the other way round.
Right: In a tack the sails flap through. In a gybe the main can stay loaded, so control the boom to prevent a violent swing.
Wrong: Release the kicker to make the boom swing more easily.
Right: Keep it on. Without it the boom rises and the upper sail can flip across violently.
6Practice case & exam keys
Running in 22 knots, you need to change gybe to clear a headland. A new crew member is sitting on the cabin roof beside the mainsheet.
Show the answer
Move everyone clear of the boom and mainsheet. If there is sea room and you can safely turn upwind, tack round. If gybing, call "Stand by to gybe" and wait for "Ready". Check the kicker is on, then bring the main to the centreline. Call "Gybe-oh", turn steadily, ease the mainsheet as the boom crosses and use opposite helm to check the turn.
Exam keys
- Gybe: stern through the wind; control the loaded boom's crossing.
- Warn crew and wait for "Ready"; kicker on, main centred, heads low; "Gybe-oh".
- Ease the main smoothly and counter-steer to avoid rounding up.
- Strong wind: tack round (chicken gybe) if you have room and can turn upwind.
Finish this unit
When you've read it, answer three questions. Get all three right to finish the unit; opening the page alone doesn't count.
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