You will surely notice the boat swinging or yawing at anchor right away, even after looking at the boat from a distance (far away). It is pretty common for an anchored boat to swing at anchor. So, what causes a boat to swing at anchor?
The boats swing at anchor because the boat becomes unstable if there are currents in the water or wind around the boat, making it swing at anchor. And the boat’s swinging or yawing also depends on the boat’s design & shape, and the swing could increase if the boat is lighter and has more freeboard.
And generally, the boat’s swinging or yawing isn’t a problem as long as other boats around you are swinging as well. The problem begins when the wind picks up and starts swinging more. Unless the boat’s swing is severe (>45° or 60° or more), you need not worry about that.
Wind and current don’t always go in the same direction. Current stays relatively constant, where the wind is constantly varying. So, the boats swing when the wind or current changes their direction. Depending on the boat, swing differs a lot.
The boats with more freeboard (the distance between the waterline to the upper edge of the deck) will swing more at anchor due to wind because more surface area of the boat will be exposed to wind, and the wind can push (swing) the boat easily, resulting in swing at anchor.
And similarly, the boats with less freeboard will not swing much due to wind because less surface area of the boat will be exposed to wind, and the wind can’t push (swing) the boat easily. However, if the heavy wind kicks in, regardless of the boat, it will swing more.
For example – Powerboats tend to swing with the wind because they have more freeboard exposed to air, more surface area is exposed to wind, making the powerboats swing with the wind outside the water rather than currents in the water.
The boats with more draft (the distance between the waterline to the deepest point of the boat) will swing more at anchor due to currents because more surface area of the boat will be under the water, and the currents in the water can push (swing) the boat easily, resulting in swing at anchor.
And similarly, the boats with less draft will not swing much due to currents because less surface area of the boat will be under the water, and the currents can’t push (swing) the boat easily. However, if the heavy current kicks in, then regardless of the boat, it will swing.
For example – Sailboats tend to swing with the current because they have more draft (have large deep keels), more surface area is exposed underwater, making the sailboat swing with currents in the water rather than the wind outside the water.
Anchored boats will swing a lot no matter what; they swing at least to a little degree. So, you can’t really stop the boat’s swing completely (to a 0° degree swing). Therefore, minimizing that boat’s swing (to the smallest degree possible) will be a better option, increasing your comfort.
Unless you have a massive displacement hulled boat (which will swing less than other hulled boats), you need to look for a solution to prevent or reduce swinging at anchor. So, that takes us to the next section of the post on “How to prevent or reduce the boat from swinging or yawing at anchor.”
How to prevent swinging or yawing of a boat at anchor?
Since the swinging or yawing or sailing of the boat at anchor can’t be stopped completely, minimizing the swing is a better alternative to increase your comfort. We will now see how to reduce the swinging or yawing of a boat at anchor.
You can reduce the boat swing at anchor by using multiple anchors or riding sail or sea anchor or anchor snubber (bridle). However, you need to pick that one that works well for your boat (after testing each of them) since each technique may or may not work for a particular boat.
A bridle or snubber attached to the bow cleats may work well for your boat (preventing the swing at anchor), but the same technique may not work well for other boats. It can be due to the design of the boat or the heavy winds or currents or anything.
Unless you try which techniques work well for your boat (in preventing the swing at anchor), you can’t simply decide the thing by looking at that technique. We will now see each of them in a detailed way.
Will multiple anchors prevent boat swing?
Using multiple anchors would be the first idea that would strike many people’s minds when thinking about how to reduce the boats swinging or yawing at anchor. But using multiple anchors for a boat will actually decrease the boat swing?
Using multiple anchors will significantly reduce the boat swing at anchor, but it is crucial to position the two anchors correctly; otherwise, it will not work. And it could sometimes be risky because other boats will swing when the wind changes direction, and yours won’t, resulting in a collision.
Since the wind or current changes are pretty common in the water and they could change anytime, so you better be anchoring your boat at a distance away from other boats to avoid any problems (collision with other boats) while using multiple anchors to avoid boat swing.
As a rule of thumb, the two anchors should be separated by at least 50° or 60° apart from each other to get the best results. Most people will use the anchor at the bow and use mushroom or grapnel anchor or any other at the stern (with no or less scope).
However, if you set two anchors down 60° apart from each other, it will reduce the swing, but if the wind or current changes direction, you have to reset at least one of them. To avoid that, some people will throw a stern anchor out (temporarily) to stop the swing at anchor.
Check this small and helpful video on using two anchors for a boat (bow and stern anchor) in a detailed way.
Will anchor snubber (bridle) prevent boat swing?
Some people call it anchor bridle, and some people call it snubber, but apart from the namings, both are the same and serve the same purpose. Will using an anchor bridle or snubber reduce the boat swing at the anchor?
An anchor bridle or snubber will reduce the boat swing at anchor to some extent (not fully, though). Connecting the two ends of the bridle (rope) to the cleats far away from the bow and the center of the bridle to the anchor rode, forming a Y-shaped structure, will reduce the boat’s swing at anchor.
Two ends of the bridal are connected to the two cleats on the boat sides (port and starboard), and it will have a hook kind of thing in the middle of the bridle rope to connect it to the anchor rode in such a way that it will reduce the tension between the anchor rode and the windlass directly.
Mostly anchor bridle or snubbers are used to reduce the windlass’s stress, but connecting the two ends of the bridle to the cleats far away from the bow will reduce the boat swing at anchor. And some people will only use a single-line snubber rather than two line snubber or bridle.
By running a single snubber line to a cleat (in the middle or at the stern), forcing the boat to ride at an angle to the wind/current will reduce the boat’s swing at anchor. However, a single snubber line to a cleat could sometimes be dangerous.
Check this short and practical video on what anchor bridle is and how to use bridle or snubbers with the anchor in a detailed way.
Will sea anchor (drogue) prevent boat swing?
Some people call it a sea anchor, and some people call it a drogue, and some others will call it a drift sock, but apart from the namings, all are the same and serve the same purpose. Will using a sea anchor or drogue reduce the boat swing at the anchor?
Sea anchor or drogue will reduce the boat swing at anchor (not fully, though), but it will reduce the boat swing if the swing is due to water’s currents, not the wind. Since the sea anchor will be in the water, it will point the boat into the waves, preventing swing due to currents, not the wind.
However, there is one alternative for this method to test whether it is working for your boat or not, which is using a bucket and tying it to the stern at the back. Many people will generally tie a couple of buckets (rather than sea anchor) at the stern to stabilize the boat in currents.
A sea anchor or drogue will help the boat point into the waves only if there is a strong current in the same direction of the swell; otherwise, it will just stay there without any use. Any sea anchor or drogue needs a current to work; without current, it is useless.
There will be times when wind and current are all coming from different directions and changing every time. A sea anchor in this situation could not work well, forcing you to look for other alternatives. So, you need to keep some alternatives as well.
Check this video on using a sea anchor or drogue or drift sock and how it is reducing the boat swing.
Will riding (anchor) sail prevent boat swing?
Riding sail is one of the most common techniques used to prevent or reduce the boat swing at anchor. And it is often used in a sailboat. Will riding sails prevent or reduce the boat swing at the anchor?
Riding sail will reduce the boat swing at anchor, and more importantly, it will keep the surging at each end of the swing way down. But they must be in the correct size for the current wind speed to work well; otherwise, riding sail will not work effectively, resulting in swinging.
Riding sails are small, efficient, and serve a specific purpose that does not change when the wind howls-keep the bow into the wind and provide steady back tension, reducing yawing and surging. It is crucial for a sailboat to have one onboard all the time.
A riding sail pushes the transom back in line when the boat sails to one side and increases windage at the stern, steadying the rode’s pull. And generally, the raiding sail helps the boat to rest at a slight angle to the wind. The combination of that will reduce the boat swing (not completely, though).
Check this practical sailor website to know more about the riding sails in a detailed way, along with the types of riding sails. Check the video below to know more about riding sail (working and using) in a detailed way.
Will rocker stopper prevent boat swing?
Rocker stoppers will not reduce the boat swing at anchor, but they will reduce the boat’s rocking motion due to the waves or wakes while the boat is anchored.
They are simple to deploy, easy to store, and an inexpensive way to smooth out that rocking and swaying motion while out at the beach, anchor, fishing, or sleeping overnight.
Rocker Stoppers help reduce the rocking motion of boats at anchor. Simply tie Rocker Stoppers approximately 44 cm (18″) apart, making a string of them, with a 5-10 pound weight attached at the bottom of the string. Hang one string off each side of the boat.
Use without a weight (or with a reduced weight) for drift fishing. Rocker Stoppers will slow down drift substantially. They are also great to use at the end of a dock to stabilize the tip from rocking. Rocker stoppers nest together, and each one is 33 cm (14″) in diameter. (source)
You will surely see or hear this somewhere, either in the forums or any, saying that, “We tried everything, anchor sail, buckets hanging from the bow and stern, dropping a spare anchor for the bow and stern, using a bridle or snubber to offset the boat from the wind. Nothing worked. We finally just learned to live with it.”
However, some techniques may work for your boat, and some won’t. Mostly, it reduces the swing, and it can’t prevent the swing in the first place. It’s all hidden in the appropriate technique and using it correctly for your boat.
Bottom line
The currents in the water and the wind around the boat will make the boat swing at anchor. The boat becomes more unstable if the currents and wind around pick up, letting it swing at anchor. And generally, boats with more freeboard will swing more than boats with less freeboard.
Using multiple anchors or anchor bridle or riding sail or sea anchor will reduce the boat swing at anchor, not entirely, though. And to reduce the boat’s rocking motion, using a rocker stopper will reduce the boat’s rocking motion.
Wind and current don’t always go in the same direction. Current stays relatively constant, where the wind is constantly varying. A whiff of air makes the boat want to go one way, and then when the wind dies down, the current moves the boat back where it was.
Finally, the boat swings a lot when anchored; the whole system is unstable, and a boat will tend to swing back and forth from side to side at anchor if there is a current or wind. They are many solutions to reduce the boat swing at anchor. Choose the one that works well for your boat.