The Most Important Parts of a Sail

There are a lot of important parts of a sailboat, but none more important and unique as the sail. Parts of a sail have different names and uses depending on whether you have a mainsail, headsail/jib, Genoa sail, Spinnaker sail, or Gennaker sail.

So what are the parts of a sail? For a mainsail, the parts of a sail include the

  • Head
  • Slides and bolt rope
  • Luff
  • Tack
  • Track slides
  • Foot
  • Clew
  • Leech
  • Batten
  • Reef cringle
  • Reef points

For a headsail or jib, the parts of a sail include the

  • Head
  • Leech
  • Clew
  • Foot
  • Tack
  • Luff
  • Piston Hanks
  • Luff Wire

Some of these parts of a sail have strange names, but each definitely serves an important purpose. Being able to identify these parts and learn what they’re used for will not only improve your sailing terminology but also your effectiveness as a sailboat captain or crew member.

Mainsail

The mainsail on a sailboat serves as an important part of a sailboat since it’s the part that acts like the sailboat’s “engine”. Of course, this is the type of engine doesn’t need any gas or petroleum. Depending on the wind strength and direction while you’re out on the water, you’ll need to adjust the mainsail from time to time to catch the wind just right.

Whenever you have the mainsail up and you have to make these adjustments, you’ll need to be aware of the different parts of a sail and what purpose they serve. Most of the time you’ll be operating a sailboat with a sloop rig (or a Bermudan rig), which is exactly what we’re going to dive into!

Head

The head of a sail is a part of a sail that’s located at the very top. With this part of a sail being at the top corner of the sail, it’s usually connected to the mast. When you have a triangular mainsail, this kind of head is what you’ll expect to see.

If your sailboat has a square mainsail, the two uppermost corners will be referred to as the head cringles where there are grommets called cringles. These cringles will most likely be attached to a peak and throat, which is a part of the mast that sticks outward.

Slides & Bolt Rope

When it comes to controlling the height of your mainsail when reefing it, your mainsail will either be attached to slides or a bolt rope. Choosing between these two types of parts of a sail are debated back and forth among sailors, so it’s important to know the difference.

Slides are probably the easiest to maintain and control when moving your sail up and down the mast. Essentially, you connect your sail to the slides and they move along the mast. However, one of the downsides is that it’s more likely that wind will get through the open spaces between your sail and the mast.

A bolt rope is popular among sailors who are active racers because it removes the gaps between the sail and the mast by integrating the sail within the mast. There’s actually a rope that’s sewn into the sail so that it can fit within a groove built into the mast. The downside to having a bolt rope is that it’s not uncommon for your sail to jam with moving it up and down the mast. Trust me, that’s no fun especially at the wrong times.

Luff

The luff is a part of a sail that’s located between the head and the tack of a sail. This part of a sail is where your slides or bolt rope will be located as well, which means it’s always attached to either the mast or a stay. Technically, the luff is referred to be located at the forward (leading) edge of a sail.

When sailing, you’ll hear the term “luffing” from time to time, which means your sail starts flapping a bit instead of being tight. Your sail will start luffing when your sailboat is steered too close toward the direction of the wind (windward) or when your sail is past optimal trim. Whenever this happens, you usually want to alter your point of sail, else trim your sail.

Tack

The tack is the part of a sail that’s placed at the bottom corner of a sail which is between the luff and the foot. This part of a sail is directly connected to the mast and boom of your sailboat as well. On any kind of sail, the tack is always located at the lower forward corner of the sail.

You’ll hear the term “tacking” whenever you’re on a sailboat, however this has to do more with an action being performed on a sailboat and not the part of a sail called the tack. Tacking is when you’re redirecting your sailboat when your sailboat is heading into the wind (windward).

Foot

The foot is a part of a sail that’s located at the very bottom of the sail and thus in-between the tack and the clew. The foot is directly connected to the boom of the sailboat and is attached using track slides. Honestly, there’s not much to talk about when it comes to the foot, which makes it more a basic term used for a part of a sail.

On a headsail or jib, the foot isn’t attached to the boom as it’s at the fore of the mast and is stabilized by the clew being attached to sheets and the tack attached to a forestay.

Track Slides

Similar to the slides found on the luff of a sail, track slides are parts of a sail that are used to connect the foot of the sail to the boom of the sailboat. Usually these are attached through the use of grommets that are connected to the boom.

It’s not too often that you’ll need to adjust these track slides since most of the time the foot of the sail doesn’t move toward or away from the mast. However, it does allow for the sail to move around freely without any restricts and it makes it easier to change out sails.

Clew

On the opposite side of the tack and along the foot, you’ll find the part of a sail called the clew. Now, the clew is located on the aft (backend) part of a sail and sits between the foot and the leech. The clew is movable and is directly connected to the boom toward the stern of a sailboat.

On a headsail or jib, the clew is connected to two sheets that are usually attached to cam cleats located on port or starboard of your sailboat. Adjusting the jib with these sheets is common when both tacking or jibing as well as when your jib’s luffing.

Leech

The leech is the part of a sail that’s located between the head and clew, which is also the longest edge and located on the aft of a sail. This part of a sail will bend based on the strength of the wind hitting the sail.

If the leech doesn’t have the proper amount of tension, it will likely start to flutter and cause a noticeable sound. This is mainly due to the fact that the leech is an arch and not a straight edge. After sailing for some time, you’ll be able to recognize this sound and tend to respond by tightening the leech line.

Batten

A batten is an important part of a sail as it helps create an efficient airfoil shape of the sail so that it provides a similar function to a wing on an airplane. Since the leech is arched and not perfectly straight, the battens help to support the shape of the sail when the wind hits it.

These battens or stiffeners sewn into pockets can either be just at the trailing edge leech of the sail or can extend right across the sail. Having full-length battens that extend right across the sail helps the sail hold the shape better.

Reef Cringle

Reef cringles are a part of a sail that is located on the bottom of the leech and luff. There are usually two or three sets of reef cringles, which are attached to sheets that are used to pull down the sail when reefing. The main purpose of reef cringles is to be able to pull down your sail to reach the proper reef setting.

Reef Points

Just like the reef cringles, reef points are a part of a sail used when reefing your sail. After you’ve reefed your sail by pulling it down using the sheets attached to the reef cringles, you’ll want to secure your sail to the boom using the reef points. You can do this by simply tying the points straight to the boom.

Headsail/Jib

Just like the mainsail, the headsail (or jib) has a head, leech, clew, foot, and tack. Any of the difference between the mainsail and jib were mentioned in the mainsail section, so I’ll bring up the unique parts of a sail that is specific to a headsail or jib.

Luff Wire

The luff wire is a part of a sail that’s located on the luff of a headsail which is attached to a forestay. Simply put, the luff wire is a metallic wire that’s inserted along the leading edge of the luff. This is a necessary part of a sail so that the headsail can stay firmly intact.

Piston Hanks

Piston hanks are a part of the sail that keeps the headsail or jib firmly attached to the forestay. These are usually made out of either metal or plastic and are designed to be easily removed using your hands. They are, however, firmly connected to the jib usually via a connector to a cringle.

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