All you need to know about jib sails

Understanding jib sails is important for any sailor, but remembering the different types and uses can get confusing. In this guide, we discuss what a jib sail is, what it does and the different types of jib sails. We’ve also got some essential tips for using a jib sail.

What is a jib sail?

A jib sail is a type of triangular foresail found on many sailing yachts and small sailboats. It’s attached to the forestay, which runs from the bow to the top of the mast and helps the boat move efficiently, especially when sailing upwind.

Jib sails are triangular, and their leading edge is called the luff. They sit forward of the main mast, usually ahead of the mainsail, and are attached using all three corners. The tack is the front bottom corner located near the bow, the clew is the rear bottom corner where the ropes control the trim, and the head is the upper corner, which is attached close to the top of the mast.

What does a jib sail do?

The main function of a jib is that it adds extra sail area, which increases speed. A jib sail also improves balance and handling of the boat, helps the boat point closer to the wind when sailing upwind, and works with the mainsail to accelerate airflow between sails for better lift.

How to use a jib sail

There are three main steps to consider when using a jib sail:

• the ropes adjust the angle of the jib to the wind
• adjusting trim changes the shape of the jib sail for better speed
• the sail can be reefed or swapped for smaller jibs in strong winds

Types of jib sails

There are four types of jib sails, and each one has its own function:

Working jib 

A working jib is a standard, everyday sail that can be used in most weather conditions. It’s medium in size, doesn’t typically extend past the mast, has a triangular shape, and is often used on small to medium cruising boats.

Working jibs are easy to trim and manage, can be balanced with the mainsail for good upwind performance, have less heeling force compared to a genoa, and offer good visibility around the sail. While they’re a great option for standard conditions, working jibs harness less power in light wind and provide slower acceleration than larger jibs.

Genoa

A large overlapping jib that extends past the mast and is perfect for use in light winds, a genoa sail boasts a large surface area and has been designed for power and speed. It’s the perfect jib option for sailing in light to moderate winds, racing, and for boats that need more drive upwind. While a genoa is great for moving quickly, it can overpower the boat in strong winds, is harder to tack than other options, and can limit visibility.

Storm jib

This small, strong jib has been designed for use in heavy weather. It has a very small surface area, is made from strong, low-stretch fabric, comes in bright colours for visibility, and has attachment points for secure rigging. This jib type is the perfect option for sailing in strong winds, offshore sailing, or when operating in emergency conditions. Plus, it reduces strain on the rig.

Furling jib

A furling jib rolls around the forestay for easy handling and can be rolled in or out to adjust its size. Furling jibs are controlled from the cockpit and are often dual-purpose, as they can act as a working jib or smaller sail when partially furled. This jib is ideal for cruising, short-handed sailing, and situations where you need quick reefing – for example, if the wind conditions suddenly change.

Tips for using a jib sail

Whether you’re a beginner or want a smoother sailing experience, these tips will help you get the most out of your jib.

Properly trim the jib

Trimming means adjusting the angle of the jib relative to the wind. When sailing upwind, pull the jib in tight so it’s nearly parallel to the centreline. When sailing downwind, let the jib sail out as far as possible. When on the beam reach point of sail, ease the jib out slightly to capture more wind. Properly trimming the jib results in improved speed and reduced heeling.

Use the jib with the mainsail

The jib and mainsail work together to accelerate airflow between the sails. You should avoid trimming one sail independently and aim to balance both for better performance. If the mainsail is flapping, tighten the jib slightly. And if the jib is flapping, ease the sheets or adjust the main.

Adjust for wind strength

In light winds, keep the jib flat for a better airflow. In moderate winds, use a standard working jib. And in strong winds, switch to a smaller storm jib.

Keep the jib clean and untangled

Keeping the jib clean and untangled will ensure it performs efficiently. Remove fishing line or seaweed from the forestay and sheets, check for snags around blocks and fairleads, and roll or furl the jib neatly when not in use.

Use halyards correctly

The halyard controls how high the jib head is hoisted, and the right tension keeps the sail flat and efficient. If the halyard is too tight, the sail can become twisted or over flattened, and if it’s too loose, it can cause flapping and your boat may lose speed.

Tack smoothly

When changing direction through the wind, ease the jib before the bow passes the wind. Then trim the opposite sheet as the sail crosses to the other side, and avoid letting the jib flap violently – this can damage the sail and slow the boat.

Practice

As with most aspects of sailing, practising using a jib is the best way to get used to it. Spend time on different points of sail, experiment with trimming and halyard tension to feel the effects on speed and handling, and learn how the mainsail and jib interact with each other.

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