The Basics of the Heave-To
While highly maneuverable and not always the easiest to execute, the fundamental premise of the heave-to is not terribly complicated.
Though the balance and the angle will be slightly different depending on the boat and the breeze, there are four basic characteristics of heaving-to.
Angle to the Wind
Though not explicitly included in the diagram, you should expect to be somewhere around 45-50° to the breeze while in this position. This should be far enough from the breeze that your main is not luffing too hard, but close enough that you aren’t powering up too much.
Jib to Windward
Now this is the most important characteristic of heaving-to. While normally frowned upon, and potentially dangerous when unanticipated, backing the jib like this is what gives you stability in this position. You trim the jib, genoa, or other similar headsail with the windward sheet and keep it locked down. If heaving-to in heavy breeze, it is good to employ a storm jib or to reef your headsail if possible to keep it from being too tensioned up in this position, as a big gust could pull your bow well off the breeze and cause trouble.
Main Trimmed
Trimming the main in this position serves two purposes. First, it balances out the jib's pull to turn downwards. This is why you would not take the main down when attempting to heave-to. Second, it preserves the main from the luffing that will age it very quickly. Moreover, if you want to exit this position, you already have your main set for the close-hauled course that you would take on right afterward. Similarly to the jib, you may find that reefing the sail helps in heavy winds, or is useful in balancing the sails overall.
Tiller to Leeward
Keeping the tiller to leeward helps you maintain this position in two ways. First, it continues to balance the jib’s attempts to draw you off the breeze. Second, by opening the rudder’s face to the water flowing under the boat, you are essentially using the rudder as a sea anchor, helping you to slow down even more and continue to hold your position.
These four steps are the baseline characteristics of heaving-to. How this will work on your boat depends on many factors that you cannot necessarily control or anticipate before you get on the water. That is why, rather than giving you a detailed boat by boat procedure, we are going to talk about some of the fundamental physics that you are working with when heaving-to, so that you know how to adjust for yourself when certain things are happening the first few times you try this out.
The Physics of Sail Control
In the type of boats with the headsail-mainsail sail plans where heaving-to is most effective, be it a catamaran, trimaran, keelboat, winged-keelboat, or simple dinghy, there are a few basic forces with which you have to contend while maneuvering of which heaving-to takes advantage. In order to talk about that, however, we first have to deal with
Centers of Effort and Resistance
In sailing in general, the goal of upwind sailing is to balance what we call the ‘center of effort’ with the ‘center of resistance.’
The center of effort is the theoretical point on your sails from which you generate all of the lifting force for forward motion. It is essentially the engine of your sails and the mathematical center of the sail plan.
The center of resistance is the point somewhere underwater on your hull -- on a keelboat it will be somewhere close to that keel -- which provides the lateral resistance that helps your boat move forward, rather than sliding with the wind.
Ideally, your boat is set up so that when you are trimmed to go upwind, the center of effort is directly above the center of resistance. Once you do this, all that lift generated by the center of effort is channeled forwards by the center of resistance. If they are misaligned, or your sails are overpowered for your boat, you will slide laterally. This is why over-heeling your boat to leeward tends to be slow and cause you to sleep sideways, as this effectively reduces the resistive force. Thus reefing, even though it lessens your sail area and reduces the lift generated, actually helps you go forward in heavy breeze as it keeps you from heeling as much and ensures that your centers of effort and resistance are still lined up.
But I digress. The real point of this is to talk about…
Sail Trim and the Center of Effort
Since controlling the balance of the center of effort is crucial to keeping your boat moving, it is useful to know how each sail affects the center of effort. On most boats, the center of effort is at the deepest part of your mainsail, called the draft, about ⅓ of the way back on that sail. This means that you can consider that as the central axis of your boat.
If you move to trim your jib -- or genoa or other headsail -- you are essentially adding more force forward of that central axis, which, in turn, pulls the bow of your boat down, away from the wind. If you overtrim your jib or, even worse, backwind it coming out of a tack, you will feel your boat pulling downwind towards a reach, or even dead downwind if unchecked.
On the other hand, if you move to trim your main in, you will be adding more pressure to the back half of your main, effectively turning your bow upwind (you can even think about it as pushing your stern downwind!).
It is this balance of jib trim and main trim that keeps your boat sailing forwards and your rudder light and helm-free. You can, in fact, use this phenomenon, along with some bodyweight steering in smaller boats, to effectively sail your boat without a rudder, either for fun or in case of a breakdown. Many double-handed race teams actually do this to practice perfecting their sail trim!
Using this to Heave-To
Ok, ok, that’s a lot of that talk, but how does this help you figure out how to find the perfect heave-to balance for your boat. Well, it actually gives you a pretty good sense!
Heaving-to takes advantage of this balance and flips it on its head. Instead of using these characteristics of the main and the jib to propel you forward, heaving-to uses them to stall out your boat entirely. By trimming the jib to weather, a move that would normally tear you down to a beam reach in a second, keeping the main working, and throwing the tiller over, you effectively have fixed your boat somewhere around 45° to the wind.
If you think about the relationships a little more, you see that each of the three main controls, jib, main, and tiller, are effectively keeping each other in check. The jib cannot pull you off the breeze because of the dual action of the main keeping the stern down and the rudder turning the boat back upwind if it gets any flow. The main will not propel the boat forward because the backwinding of the jib is choking off its airflow, and even if it did get moving it would push too close to the breeze and start luffing. Finally, the rudder, positioned as it is, both acts as a brake against the water underneath and helps keep the boat from turning down, which could end this game of dynamic tension.
Troubleshooting
Because this balance relies so much on the individual characteristics of your boat, it is difficult to say exactly what trim settings you will need to maintain this position for a long time. Therefore, it is up to you to experiment!
If you find that your jib is overpowering your mainsail, pulling you off the breeze, you may have to either reef the jib, push the tiller over farther, pull the jib farther to weather, or get more power in the main. With the opposite problem, you may find it necessary to reef the main quite a bit, or find a better way to haul your jib to weather. It is good to have a rough guess of how to set your boat to heave-to in various wind conditions, as it may be different across sea states and breeze strengths, so I would encourage you to try it out a few times on a few different days so that you know before you need it!
How to Heave-To
After all of that, I would be remiss not to give you the rundown of the easiest way to get your boat in the heave-to position. While it is occasionally possible to simply sail upwind, luff your sails for the moment, and heave your jib to weather, this is not necessarily the most efficient way to do it, and it can put excessive strain on your sails and sheets (and yes, that really is why they call it ‘heaving-to!’).
In general, you accomplish the heave-to by sailing upwind then turning your boat into a nice, slow tack. As you do this, keep your headsail trimmed to the sheet on the old tack, so that when you come out of it, you are trimmed on the weather side.
As you come out of the tack and the backwinded jib is trying to pull you off the breeze, keep your tiller pushed, or wheel turned, to leeward. If you don’t overdo it, the fight between the jib pulling you down and the rudder turning you up should stall your boat out so that you are more or less stopped in the water. Throughout this whole process, the main should be trimmed-in, approximately to where you have it when sailing close-hauled, a little looser if anything, but not luffing.
When you find the point where the main is not ragging, the jib is full but not pulling you down, and the tiller is set, you have effectively heaved-to! Again, finding the right balance may not be that easy, and may require various reefing, trimming, and steering adjustments. These are too many to count, which is why I hope the explainer on the various forces that you are trying to balance will help you diagnose any potential issues you have so that you can make these adjustments as you go!
You should find that this is a highly effective way to stop your boat without the need to drop anchor or your sails. In fact, the little forward progress that you will make from the fact that your sails are still filled should be just about enough to keep your position against the wind and the waves, which would drive you backward in any other unanchored arrangement.
Like anything else in sailing, however, it takes a few attempts, a couple of tweaks, and a good feel for your own boat to master the heave-to, so I hope you take this as a good excuse to get back on the water. Happy Sailing!
