A sailboat will heel or lean over at an angle when you sail in any direction other than almost straight downwind. The wind pressure on the sails will force the vessel to a sideway angle, while the righting moment of the keel’s weight and lateral resistance in the water counteracts this energy. When a sailboat tilts over like this, it is called heeling.
For a beginner, heeling over can be intimidating and feel unnatural, and I have seen many white faces on their first sailing trip. I certainly remember my heart beating a bit faster during my first sailing experience.
In this article, I’ll explain everything you need to know about sailboat heeling. I’ll xplain why it happens, and how to control and use it to your advantage. We’ll also cover how to adjust your sails and rigging to reduce or increase heeling, and how to deal with different conditions effectively.
Why do sailboats heel over?
To be able to sail at any angle to the wind, a sailboat needs to take advantage of the wind’s force in the sails to make it move forward.
When air hits the sails at the right angle, it generates lift. Some of the energy will force the boat forward, and the rest will try to push the boat sideways through the water. However, the sailboat’s keel prevents lateral movement sideways to a certain degree, and the remaining energy will make the boat move forward at a sideway angle.
The closer to the wind you sail, the more you heel. As you fall off and start pointing away from the wind, the boat’s heeling angle decreases. Eventually, you will reach a point where you are sailing directly downwind, and the keel doesn’t need to work as hard to provide lateral resistance and move the boat forward because the wind is already blowing in the direction you want to go.
What is the optimal heeling angle?
Some boats like catamarans, trimarans, and planing racing monohulls are designed to be sailed primarily upright. Most cruising monohulls, however, are displacement boats and have to heel to go forward when sailing at an angle to the wind.
Most cruising sailboats generally have an optimal heeling angle of 10-20 degrees. When sailing close-hauled, you might have to push it down to 25 degrees to keep your forward motion, but heeling too far will probably make you slower. 10-15 degrees is a good compromise between performance and comfort.
We have a simple method to find the best heeling angle for our particular boat in the conditions we are sailing. When the boat heels over, it will try to turn itself back up by turning into the wind. This is called weather helm.
To keep the boat straight on course, we compensate for the weather helm by countersteering with the rudder, which also generates more lift up to a certain point. Compensating too much makes the rudder act like a break, which will slow us down.
Keeping the angle of the rudder between 2 and 7 degrees gives you a nice balance between performance and heeling angle. On many cruising boats with a steering wheel, keeping your center mark between ten and two o’clock is an excellent rule of thumb.
How do you control heeling on a sailboat?
There are several ways to control and reduce the heeling angle when sailing, and there are good reasons why we want to.
A typical scenario is when you are sailing with a good balance on the helm at a decent heeling angle. Then, all of a sudden, the wind increases, and the boat starts to heel excessively. As a result, you get more weather helm as the boat tries harder to round up into the wind, and the wheel gets hard to control.
The boat is now overpowered, and you are heeling too much.
Luckily, we have three easy ways to prevent the boat from heeling too much:
- Adjust sail trim
- Adjust course
- Reduce sail area by reefing
Let us take a look at each of our options.
1. Adjust the sails
De-powering the jib or genoa by easing off the sheets or letting out the mainsail traveler is a quick way to regain control over the boat. If you sail on a reach, easing the sheets will turn the sideway force into forwarding force. When eased far enough, you are actively releasing the wind out of the sail, and the sail will start to luff.
When sailing downwind, easing the sheets is the only viable way to de-power the sails quickly, as you might be unable to turn the boat around and back into the wind. If you get too overpowered, you risk broaching, which can be dangerous.
If the wind increase was just temporary gusts, you might want to either actively work on releasing and pulling the sheets, often referred to as “pumping,” or settle for lower performance and slacker sheets. When you sail upwind, this works as a quick way to de-power the sails, but working with the sheets for every gust means you will lose height and not point well.
2. Adjust the course
Turning the boat into the wind will take power out of the sails and is easy to do when sailing upwind. When we sail close-hauled, we have a trick we can apply to increase our performance.
A powerful ” feathering ” technique is simple to apply and works well when sailing upwind. Instead of easing the sheets in a gust, you keep the sheet tension and steer the boat higher into the wind. As the apparent wind angle moves aft when the strength increases, we use this to our advantage to keep our height by sailing to the angle of our heel instead of the angle of the wind.
I wrote an article about how high a sailboat can point that you might be interested in: How High Can A Sailboat Point?
Feathering requires an active and focused helmsman, and as soon as the gust stops, you have to fall off again to keep your heeling angle and not lose power in the sails.
Continuing to fall off and bear away while easing off the sheets will also calm the boat down and make it turn more upright. This technique is helpful if you get tired or feel like you are pushing yourself and the boat too hard. Adjusting the course to a downwind point will also reduce the apparent wind speed and can be a good solution if you need a break.
3. Reduce sail area by reefing
When the wind isn’t just gusting but steadily increasing, it is about time to reduce your sail area by reefing. If the boat is heeling more than 20-25 degrees, you have too much canvas exposed, and reefing at this point will make you sail faster, safer, and more comfortably.
It is advisable to reef earlier rather than later as it can be hard to control the boat when it gets overpowered. Pushing limits while sailing is only for experienced people, and any seasoned cruiser agrees that a conservative approach to increasing weather is smart. If you ask yourself, “Should I take a reef?” the answer is always a big yes.
The reef can easily be shaken out if your hunch was wrong or if it was just some gusts or a short squall. Conservative and safe are the magic keywords. Even if you aren’t anywhere near the maximum heeling angle, less sail area can give you a much more comfortable ride with less heel, even if it means sacrificing a little bit of speed.
How far can a sailboat heel before capsizing?
I get this question a lot, especially from those sailing for their first time. When sailing close hauled, we sometimes push the boat to the point where it may seem like we will tip over and capsize. I often see faces going white when the toe rail dips into the water… Luckily, sailboats are designed very cleverly.
The wind can not heel a sailboat over far enough to capsize. Sailing boats are designed to round up into the wind if they are overpowered and heeling too much.
It is nearly impossible to fight the helm hard enough for the boat to tip over, even if you want to. And if you could, the rudder will eventually lose grip in the water, and the boat will round up until it points upright into the wind with its sails fluttering.
However, you want to be careful when sailing downwind, especially with a spinnaker. As you are sailing off the wind, your apparent wind is lower than your true wind, and sometimes, it can be hard to notice wind increases. Since the boat doesn’t heel over as much as it does upwind, everything might seem fine until you suddenly are overpowered and going too fast.
Getting overpowered can lead you to a broach, which can knock you over in extreme cases, especially if the waves are big. A keelboat will turn itself around again, but you will probably lose your mast and sails, and we want to avoid that!
Monohull sailboats do heel, and they have to in order to generate forward momentum. How far they heel dramatically depends on the boat. They won’t tip all the way over, even if it may seem so, and will usually round themself up into the wind, where you will be left upright with fluttering sails.
Heeling too much is unsuitable for comfort or speed, and finding a good balance of sail area and weather helm will give you the smoothest ride. Be careful, reef early, and don’t push the limits. Sail your boat conservatively until you gain more experience, and remember to enjoy yourself on the water.
If you want to learn more sailing basics, visit my beginner’s guide here.