How to Trim a Jib: Sheet, Car Position and Halyard

To trim a jib, set the course first, then ease the sheet until the luff starts to flutter and sheet in until it just stops, with both luff telltales streaming. Adjust the jib car so the top, middle and bottom telltales break together: move it forward if the top lifts first, aft if the bottom lifts first. Tighten the halyard as the wind builds to keep the draft forward, and ease it in light airs for a fuller sail.

The three controls

Jib controls and what they do.
Control	Effect	Adjust when
Sheet	Angle of the sail to the wind and leech tension	Every course change
Car (fairlead) position	Twist: how open the top of the sail is	Wind strength or point of sail changes
Halyard or luff tension	Position of the deepest part (draft) of the sail	Wind builds or eases

Step by step

Steer your course. Trim follows the course, not the other way round (except when sailing close-hauled, when you trim then steer to the telltales).
Ease the sheet until the front of the sail just starts to bubble, then sheet in until it stops. Check both luff telltales are streaming. See how to use telltales.
Check twist: head up slowly. If the top windward telltale lifts first, the top is too open: move the car forward. If the bottom one lifts first, move the car aft.
Check the halyard: horizontal creases from the luff mean too little tension; a vertical crease along the luff means too much.
Look at the leech: close-hauled, the leech should sit roughly parallel to the mainsail and not hook in towards it.

How trim changes with wind and course

Light airs: ease the sheet a little and move the car forward for a fuller, more powerful sail. Ease the halyard slightly.
Medium wind upwind: sheet in until the foot is close to the shrouds or spreader, but not touching.
Strong wind: move the car aft to twist off the top and depower. Tension the halyard. If still overpowered, partly furl or change down.
Reaching: ease the sheet well out. Move the car forward or outboard if you have a barber hauler, so the leech does not fall open too much.
Downwind: the jib is often blanketed by the main. Pole it out or sail broader reaches; see what is a broad reach.

Furling genoas

A partly furled genoa gets baggy and its clew rises, so the sheeting angle changes. Move the car forward as you furl, roughly so the sheet bisects the clew angle. Many boats mark car positions for each furl on the track. Remember the winch handling basics in how to use a winch safely.

Then balance the boat with the main: see what is weather helm and the sail trim lesson.

Related guides

Frequently asked questions

How tight should a jib sheet be?

Just tight enough that the luff stops fluttering and both telltales stream. Over-sheeting stalls the leeward side and slows the boat even though it looks tidy.

Which way do I move the jib car?

Forward for more power and less twist (top telltale lifts first, or light air). Aft for less power and more twist (bottom lifts first, or strong wind).

Is a genoa trimmed the same as a jib?

Yes. A genoa is a large headsail that overlaps the mast, so it is sheeted further aft and outboard, but the telltale and car rules are the same.

Start revising

← All guides Start the free theory course →