What is the correct verb (or phrase) to describe the action of reducing a boat's sail power in a heavy storm? So far, I've only come up with reefing the sails, but that refers to the furling of the sails around their respective beams. This is a rather slow process; I'm looking for something that refers to a quick, decisive action taken in an emergency -- for example, when the wind shifts suddenly or the boat threatens to capsize from too much force exerted on the sails.

Personally, I would call it easing up or letting up the sails, but that's only a landlubber's guess.

  • 4
    From the plethora of answers, you might see the problem with the question: sailing terminology is extremely precise, because the words derive from a command-giving context where imprecision or ambiguity can spell death. There are only general terms for things that are meaningful in general terms. Commented Sep 7, 2012 at 21:23
  • 2
    This Q is why we need to get the Recreational Boating site up and running.
    – bib
    Commented Sep 8, 2012 at 0:30

8 Answers 8


There isn't a single way to reduce "sail power", hence no single term for this. There are several terms for specific actions that may or may not do the job, depending on the circumstances being reacted to. Reviewing some of the more likely and less likely ways to accomplish a reduction of sailing power, you can see that there's no word that is exactly what you're looking for:

  • One may douse the sails, if the rigging is such that suddenly dropping the sails is possible.

  • You can ease (not "ease up") anything under tension, including sails' rigging. The lines controlling the sails are the sheets and the most likely candidate for emergency easing. This can be done quickly, though loose, flapping sails can be dangerous, especially with larger sails, so easing an entire sail is not a default emergency measure.

  • The boat can be put in irons (i.e., robbing it of all wind power and getting it "stuck") by turning it directly into the wind, but that's a fairly drastic effect on one's control of the boat for little gain. Conceivably, in an emergency that could be an intermediate action to gain some breathing space to deal with the sails directly.

  • More abstractly, you can bleed wind from the sails, but that doesn't describe a specific action. Actually, this may be closest to what you're looking for, as it describes a specific kind of reaction to an emergency. It's not a general term, though, as it doesn't cover dousing or reefing, for example. It's an appropriate measure when just a little bit less wind will correct a problem or impending capsising, so possibly not the term to use when responding to a sudden storm.

For reference, reefing sails actually means to tighten them to their minimal area without entirely removing them as wind surfaces. Furling is to wrap a sail so it has no wind surface. Depending on the rigging, reefing may be a necessary part of the process of furling a sail.

  • "in irons" refers to being stuck head into the wind: not moving, and not being able to (easily, if at all) turn the boat. Simply turning into the wind is not the same as being in irons. Commented Sep 10, 2012 at 4:40
  • @Ward Right; would adding "directly into the wind" make the intention clearer? I was trying to do an exhaustive look at the various terms to demonstrate that none of them are exactly what the OP is looking for. Wait, maybe I should say that? :) There, edited. Is that an improvement? Commented Sep 10, 2012 at 18:01

Generally, any action to reduce the wind surface of the ship's sails or their ability to pull on the ship will reduce the "power" of those sails. There isn't one way to do it, and so there isn't one term for it. The main methods on a square-rigger (which includes most of the iconic "tall ships") are to reduce or minimize the sail's surface area, or to turn the ship so that the wind blows across them instead into them.

The normal way to stop a ship in open water usually doesn't involve taking in sail (at least not till after the ship has stopped); instead, the sails and the ship are positioned so that all the forces on the ship are cancelling each other out. This process is called "heaving to", and on a square-rigger it's done by turning aside to the wind, then literally heaving the jib sails to windward (pulling the windward sheetline taut and letting go the leeward); this angles them so they push back against the rest of the sails, bringing the ship to a stop; the next command, if they are to remain stopped, is usually to "take in sail" or "dowse canvas".

The fastest way to properly stop using a sail is to "take it in" or "put it in its gear". The sheetlines (and tacklines of a course sail) are loosened ("let go"), slackening or freeing the lower edge of the sail, and then the clewlines and buntlines (stretching from the yard down the height of the sail to the lower edge) are hauled from the deck to pull the sail up to the yard. Originally, the buntlines were simply attached to the bottom of each sail, and as they were hauled the sail folded in half. That advanced to a system where the buntline goes around the entire sail and is anchored on the yard; as it's hauled the sail is pulled more compactly up under the yard. The sail is then said to be "in its gear". Only the course (lowest) sail of each mast could be put in gear completely from the deck; the sheetlines of the topsails, topgallants and royals were usually attached to the yard of the sail beneath, and so to furl those the sheets first had to be disconnected, by climbing out to the yardarm of the next lower sail and freeing the sheetline. Not a job for the faint-hearted (really, there's no job aboard ship that's for the fainthearted).

If there's time and ability, and the sail isn't to be used for a while, the crew would then properly "stow" or "furl" it by tightly binding it to the yard with its gaskets. This is normally done prior to a storm if at all possible; if the ship is caught in a sudden squall, putting the sails in their gear is usually enough.

To lower the center of gravity of the ship (useful in a storm), the halyard which supports the yard spar of the sail can also be let go, which on older large ships allows the yard to be "sent down" all the way to the deck (an operation requiring a lot of manpower to be done quickly and not usually done while actually in a storm). On newer and smaller ships this usually doesn't happen, but those ships often have "lifting yards" which can be raised and lowered along a section of the mast; in their lowered position they're easier to get to and the weight of the yard and sail is carried lower to reduce rolling in high seas.

As a stopgap in a hard blow, the ship may turn 90* to the wind and "square sails"; the "braces" (lines controlling the angle of the yard to the ship) are hauled to literally square the yards, and thus the sails, perpendicular to the ship's center line. That would cause the wind to blow across the sails instead of filling them, giving the crew time to strike and stow them. This is useful in high straightline winds, less so in cyclonic winds (where the direction of gusts may change often).

Completely freeing a sail by cutting it loose was an absolute last resort, usually when one or more of its brace, tack or sheetlines had failed, causing the crew to lose control of the sail, and the sail was threatening to take its yard and maybe the mast with it. Freeing a square-rigged sail requires climbing up onto this unstable sail's yardarm and cutting all its robands off the jackstay, freeing the mast from the yard, then cutting all the clewlines, buntlines, tacks and sheets to let the sail blow away. The sail was very unlikely to ever be seen again, much less recovered, and there was always a chance that the sail could foul on one or more other lines as it blew away, creating even more problems. Most often, this would be done to the jibs; on a tall ship these were typically the easiest to get rid of in this manner, the least likely to foul, and the least vital sails when underway (they help trim the ship and are used to heave to but none of these maneuvers absolutely require them, and they're not used at all when sailing before the wind).

Understand that even in a storm, some sail has to be hung if the ship isn't anchored; a ship with all sails furled can't control where it's blown, and just tosses about in the waves. So, you have to hang some canvas; good options are the course and lower topsails of the foremast. These normally can't be reefed on a square-rigger, but that's why you have so many different sails, so you can adjust how much wind you catch and how much is aloft.


Luffing up is turning into the wind to reduce pressure on the sails, and is often done in gusts; or you can let fly the sheets in an emergency, allowing the sails to flap freely (though, as SevenSidedDie says, this can have its own dangers).


The usual action taken in heavy gusts is a combination of letting out the main sheet (the rope controlling the mainsail) and luffing up, which is turning the boat towards the wind direction. This is almost a reflex response to heeling from the strong gusts and is the quickest method of keeping control. Not a single word, I'm afraid, but I'm not sure that one exists.

  • It's not a reflex, it's just the way a well-designed sailboat works! As the angle of heel increases, the centre of resistance of the hull shifts forward, which causes the boat to tend to turn upwind (since the centre of effort of the sails hasn't moved). Commented Sep 10, 2012 at 4:46
  • Of course, that's what I meant to say! Having said that, letting out the main sheet is almost a reflex response. And I did say almost. Commented Sep 10, 2012 at 21:07

As an emergency measure you can "release the sheets", which are the lines that hold tension on the mainsail boom and the jib corner (clew). Doing this will release most of the wind pressure on them, with the main boom pointing downwind and the jib flapping free in the wind.

This is very fast to do as it only requires releasing two sheets (in a sloop) from a jam cleat or cam cleat.



The general term for reducing the amount of sail area is "shortening sail." Reefing, furling, and changing to smaller sails are specific ways of shortening sail.

More detail:

Using a sloop rig as an example, to reduce power and sail area as the wind increases, you'd typically do the following, in approximately the following order:

  • Without changing the amount of sail area, you can "flatten" the sails (by tightening certain control lines, e.g. http://www.epsails.com/Mainsail_trim.htm)

  • Most boats have multiple jibs (the sail in front of the mast) and as the wind increases you switch to progressively smaller ones.

  • Although jibs can be reefed, in a modern sloop rig, it's generally the mainsail that's reefed. Basically, the sail is lowered part way and secured with reef lines in the new, smaller, lower center of effort configuration. With modern rigging, this isn't slow, but in a storm it can be exciting.

  • "Furling" a sail means to roll and bundle it up for storage. Roller-furling jibs are often used as a way of reefing by partially rolling up the sail. It's not as effective as true reefing because it doesn't lower the center of effort of the sail, and in a strong winds the sail can be stretched out of shape, but it's often a quick solution.

  • To ride out a severe storm, the final step is generally to set a trysail, a small, strong sail that gives you some sail area, but not enough to overpower the boat.

SevenSidedDie mentioned easing... You don't ease sails, you "ease the sheets:" let out the lines that control the sails. This reduces the sail' power in a puff of wind. If you let the sheets out a lot, the sails will luff (flap in the wind) and give you no power, but in a storm that will damage the sails very quickly.


Reefing is appropriate, but as you say isn't easy in a storm. Basics of reefing

A more urgent method of reducing sail is to drop the sails, which basically lowers them quickly to the deck. It appears to be an emergency course of action. How to sail in bad weather


Perhaps this will help:

Bring by the lee To incline so rapidly to leeward of the course, when the ship sails large, as to bring the lee-side unexpectedly to windward; and by laying all the sails aback expose her to the danger of upsetting.

  • I think the modern term form this is gybing: if so, it's the precise opposite of what was asked for. Commented Dec 22, 2012 at 22:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.