How do you gybe a sailboat?

Bear away from a broad reach to a run, call “Ready to gybe”, and pull the mainsheet in to bring the boom towards the middle. Call “Gybe-oh” and turn slowly until the stern passes through the wind and the boom crosses. Ease the mainsheet out on the new side, steady the boat and bring the jib across.

A gybe (spelt jibe in American English) turns the stern of the boat through the wind, the opposite of a tack, where the bow goes through the wind. In a tack the sails flap as you turn; in a gybe they stay full of wind the whole time, which is why the boom can come across a gybing boat so fast. Done carelessly a gybe can be violent, and it causes many injuries on yachts; done properly it is gentle.

A safe gybe depends on the mainsheet. The further the boom has to travel across the boat, the faster it is moving when it reaches the other side, so bring it in towards the middle before you turn.

1. Get ready. Start on a broad reach. Check the water around you is clear and call “Ready to gybe.” Everyone keeps their head low, well out of the way of the boom and the mainsheet.
2. Bear away to a run, with the wind almost directly behind you.
3. Pull the mainsheet in, bringing the boom towards the middle of the boat.
4. “Gybe-oh.” Call it as you start to turn, and turn slowly. As the stern passes through the wind the boom swings across, but only a short way.
5. Ease the mainsheet out smoothly on the new side, and steady the tiller so the boat doesn’t swing round towards the wind.
6. Bring the jib across, trim, and settle on a broad reach on the new gybe.

Remember: main in, then turn.

An accidental gybe happens when the wind gets behind the mainsail on a run and the boom crosses without warning, from fully out on one side to the other. Avoid it by not steering too far downwind, and on a long run rig a preventer to hold the boom out.

If it is blowing hard and you are not confident of the gybe, head up, tack, and bear away again on the new side instead. It takes longer but is much gentler on the boat and crew.

More in the book: Chapter 7, Gybing and sailing downwind