Updated on February 9, 2020

Does the idea of strong winds when out sailing freak you out? Plenty of sailors miss great sailing days for fear of squalls or increasing winds. But even if you do get caught out with strong winds approaching, you don’t need to worry. Once you learn how to reef a sail, you’ll be able to confidently sail in any condition.

Sailboats are made for the ocean and its weather. That’s why all it takes is learning how to sail to be safe. When yachts get into trouble, it’s often the crew at fault rather than a flaw in the boat! Understanding how wind strength and sail plan affects your sailboat will give you the tools to fearlessly go on an adventure.




Reefing is simply making a sail smaller. This is usually done in response to the increasing wind. Reefing down a sail allows you to continue sailing without being overpowered. This keeps the boat under control and often makes the journey more comfortable.

A sail that is too large for the wind conditions could be dangerous as it provides too much resistance for the boat. Putting off reefing, especially for a squall or very strong winds, is a bad idea. It can result in the sail ripping, the boat heeling over dangerously or even the mast breaking.

Reefing can seem overwhelming but in reality, it’s a fairly simple action. Once you’ve reefed, even strong winds will seem considerably more manageable and the conditions will be far less daunting.




When you need to reef will depend on the boat you’re sailing. Some boats will need to be reefed considerably earlier than others. Lightweight yachts often need reefing much earlier than heavy, more traditional yachts.

If your sailboat has a heavy, full keel, chances are you’ll be able to hold full sail for longer than a fin-keeled lightweight cruiser. In increasing winds and relatively safe waters or conditions – small waves, daylight – you can wait until the boat feels like she’s starting to strain before reefing.

In more difficult conditions – large waves, twilight or dark – you will want to reef in anticipation.

Unless you are continuing a particular course, you may not need to reef at all. If you need to turn downwind, for instance, you can turn sooner and keep a full sail.

Often, you can reef just the foresail to reduce pressure while keeping the center of effort further aft for better performance (unless you’re a catamaran).





Mainsails have reefing points sewn into them when they are made. Yachts expecting strong winds may well have a three-reefed mainsail. This gives them more opportunity to reef in different winds. Day sailing yachts might only have one or two reefing points as they wouldn’t be out in exceptionally strong winds.

To reef the mainsail, the boat must be turned up into the wind to take the pressure off. You don’t want to turn it so much that the boat tacks itself or that the foresail starts flogging madly. Easing the mainsheet will also help take off the force.

After the pressure has been taken off the sail, you’ll need to release the kicking strap/vang (the rope or arm holding the boom down) and tighten the topping lift. The weight of the boom will now be taken on the topping lift and not the sail.

After you’ve reefed and tightened up the main halyard again, you can loosen the topping lift and tighten the kicking strap/vang.



Slab reefing is the preferred method for serious offshore sailors including the famous Skip Novak. This is the act of folding the bottom of the sail down until you reach your desired reefing point. In slab reefing, the mainsail is lowered down onto the boom and then secured at it’s new smaller size.

Many modern yachts use a lazyjack system which creates a pocket for the mainsail to reef down into. If your lines lead back to the cockpit and you have a single-line reefing system, the process is straightforward.

Simply lower the main halyard down until the reefing point reaches the boom. Then, cleat it off. Pull the reefing line until it tightens the luff and leech of the sail.

With lazyjacks, the excess material will be safely contained. Without lazyjacks, you’ll have folds of material flopping around the boom. You’ll need to tie these using the metal eyes sewn into the sail along the reefing point.

If you don’t have lines leading back to the cockpit, you’ll need to reef the sail while standing at the mast. After lowering the halyard to the reefing point, you can hook the reefing point and pull the reefing line to tighten the new foot.



In mast reefing is popular with modern yachts and charter yachts. This type of reefing rolls the mainsail into the mast as opposed to dropping it down onto the boom. In mast reefing is usually very straightforward and extremely quick. This is performed by pulling on the furling line.

Long-distance sailors or sailors likely to encounter unpleasant conditions may steer away from in mast reefing. This is due to the risk of the furling system causing a mast jamming. In a jam, it may become impossible to reef the main or take it down at all. This situation can quickly become extremely dangerous.



Boom reefing is where the mainsail is rolled around or furled inside the boom. Possibly the least popular type of furling, boom reefing can be difficult and has a few downsides to it such as the boom becoming larger than it would be otherwise and the shape of the sail getting lost.

Boom reefing is performed simply by releasing the main halyard down and pulling the furling line until the sail reaches the desired size. Boom reefing technicalities depend on the make of the furler but are usually very easy to operate.



Foresail reefing is quick and easy. It is a great way to reduce overall sail area fast. Many yachts perform best with the power in the center of the boat, i.e. the mainsail. So, reefing the foresail before the main can be ideal to maintain the forward drive.

Most sailboats have a roller furling system for the foresail and reduce the size of the sail to however small they like. Reefing a foresail requires easing out the sheet so that the sail loses the wind and the pressure is taken off.

Then, you can pull in on the foresail reefing line until the sail is the desired size before cleating off. Winch in the sheet until the sail is set and you’re reefed down!



While we’ve only talked about reefing a sloop, you can reef almost all sailboats. The only boats that you often cannot reef are those with hanked-on sails. When the wind gets too strong in this case, the sails must be swapped out for small ones.

Reefing catamarans is a good example of needing to reef the main and not the foresail. The foresail of a catamaran creates an upward lift, which is important to prevent the cat from burying its bows.




Reefing either sail will slightly change the way the boat is handled. Depending on which sail is reefed or reefed the most may cause the boat to come up into the wind or bear away from it. The helmsman will feel the change and should adjust the steering accordingly.

If the reefing caused the boat to drop a large amount of momentum and is suddenly slopping about in the water, you have reefed too much. In gusty or squally conditions, it can be difficult to know how much to reef or exactly when to reef.

If you see a squall approaching, you may have to put up with wallowing a little under a deep reef before the squall hits you. When it does though, you’ll be glad you reefed!




Reefing is an essential skill for sailing. However, the fundamentals are so simple that you’ll soon easily get to know the reefing systems on your boat or the boats you sail. Having the knowledge to reef will give you the confidence to go out sailing in some great conditions.

A great tip for setting out into strong winds is to reef before you even leave the harbor! It’s often easier to put out more sail than to reef it in. So, start smaller if you think the wind strength might call for it.