How to Anchor a Boat
Mastering the Art of Boat Anchoring: Your Essential Guide on How to Anchor a Boat
Many a leisure sailor will recognise the creeping anxiety that can begin when it’s time to anchor your boat. Although the technical basics are taught by sailing schools, there is much more to anchoring than simply lowering the anchor. A comfortable and safe overnight stay at anchor is a mixture of skill, art and, at times, luck. For all of its importance, it is barely covered in sailing tuition and is something that is learned more through experience. As a result, many cruisers simply never anchor. Yet this is to greatly reduce cruising range and many great adventures will simply not be open to you.
In this latest Rubicon 3 Pro-Guide, we share with you the knowledge, skills and experience of our expedition skippers – skills that will enable you to set anchor up in wonderful, remote and beautiful places.
Rubicon 3 are Europe’s #1 adventures sailing school. Learn from the pros!
- There are numerous different anchor designs. Choose the right anchor for your boat’s size, weight and design according to its intended use and likely bottom conditions.
- Prepare anchoring gear properly before you arrive.
- Follow a slow, professional routine for anchoring and weighing anchor to achieve maximum success each time.
Choosing the Right Anchor for Your Boat
Don’t presume the anchor sitting on the front of your boat is necessarily appropriate for what you need. Many mass manufacturers are fully aware that you will anchor your boat only occasionally and probably in the safest conditions. As a result, they are unlikely to invest money and reduce profit by putting a top-quality or larger anchor onboard. However, as we found many times while anchoring in remote and wild conditions on our Arctic Expeditions, all anchors are not equal and making a change can yield huge benefits. Your yacht must have at least one anchor, but a well-fitted yacht will have at least two anchors, with the second kedge anchor being held in reserve. Heading off with a single anchor, you will eventually come unstuck (excuse the pun!)
Types of anchor
In almost all cases, anchors work by laying on the seabed and then the flukes digging in, first at the tip and then expanding the hole to take an ever-wider section. Anchors are designed to lay flat on the seabed, with the rode following the line of the shaft before curving upwards towards the boat.
- Plow anchor (CQR): This is the most popular yacht anchor due to its versatility and effectiveness in various bottom types. It’s particularly good in soft mud, sand, and clay. Pros: Plow anchors well in a variety of bottoms, is easy to stow and can handle moderate winds and currents. Cons: Can snag on rocks or hard surfaces and may drag in deep water.
- Danforth anchor: This lightweight anchor is popular for its ease of use. It’s well-suited for sandy and muddy bottoms but is best suited to shallow water and can struggle in deeper water or with strong currents. Pros: Lightweight, easy to deploy and retrieve Cons: Less effective in deep water or with strong currents. Can snag on rocks or hard surfaces.
- Bruce anchor: This anchor, also known as a claw anchor, is known for its holding power and resistance to drag and works well even in deep water. It’s particularly effective in soft mud, sand, and clay. Pros: Strong holding power, good for deep water and strong currents, and can handle a heavy load. Cons: More expensive than other anchors, heavier, and may not be ideal for shallow water.
- Spade anchor: The Spade anchor is a newer design that has gained popularity for its exceptional holding power, especially in deep water and strong currents. It features a deep, pointed fluke and a wide, flat base, resembling a spade. This design allows the anchor to penetrate the bottom deeply and spread its weight over a large area, providing superior resistance to drag and slippage
- Mushroom Anchor: Shaped like a mushroom, with a wide, flat base and a narrow shaft, mushroom anchors are useful but only in very particular conditions. They need a soft bottom for the cup to settle into and fill. They can then hold up to ten times their weight and because they are buried, are not very susceptible to shifting tides or currents. As a semi-permanent mooring they work well, but for cruising they are not a viable option
Assessing Anchor Size and Weight
Apart from the anchor design itself, the weight of the anchor plays a key role in how effective it will be. What weight you need depends on several factors, including your boat’s length, displacement, intended anchoring conditions, and the type of bottom you expect to be anchoring in.
Boat Length and Displacement:
A general rule of thumb is to use an anchor that weighs approximately 1 pound (0.5 kilo) for one anchor for every foot (0.3 metres) of boat length. For example, a 30-foot (9 metre) yacht would typically use a 30-pound (14kg) anchor. However, don’t be too literal with this, as the best weight of anchor for you will depend on a range of other factors
Intended Anchoring Conditions:
If your cruising plans mean you are likely to be anchoring regularly in deep water or strong currents, you will need a heavier anchor than if you are only anchoring in shallow water or calm conditions. A bigger, heavier anchor distributes its weight over a larger surface area, allowing for deeper and more effective penetration of the flukes. It also makes the fluke anchor less susceptible to being floated up by currents or pulled out by drag.
Type of Bottom:
The type of ocean floor or bottom you will be anchoring in will also affect the weight of the anchor you need. Anchors that are designed for soft bottoms, such as mud or sand, will typically be lighter than anchors that are designed for hard bottoms, such as rocks or coral.
Planning where to anchor
This can be the million-dollar question, and if we got it right every time we’d be delighted. Proper planning will get you most of the way. Nothing beats local knowledge. Ultimately, however, there are so many variables that an element of luck nearly always comes into it. However, we have a checklist to work through:
- Wind Direction and Strength: Always start by assessing the wind direction and strength to determine if an anchorage will offer suitable protection. Ideally, you do not want to be on a lee shore, where a dragging anchor will leave you drifting onto rocks. However, in some anchorages, especially basins, this may simply not be possible.
- Bottom Type: Choose an anchorage with a bottom type that will allow your anchor to hold. A sea bed with soft bottoms like hard sand, mud and clay, are ideal. Beware that fine sand may not provide good holding at all. If the bay has lots of kelp or weed, you may also struggle to get a good hold. The same is true of rocky bottoms, where you have slightly to hope that you find a patch of sand or mud.
- Size and proximity to hazards: The average anchorage only needs to be around 70-100m wide to allow most yachts to anchor in it. However, this will feel extraordinarily close and tight when you arrive, so make sure you have measured it on the chart and that your yacht can fit. Check also for rocks and reefs that may make part of the anchorage unsafe. Another hazard is permanent moorings that have a chain on the ground and just love to snag an anchor!
- Charts and sailing guides: Look for that anchor sign on your chart and use a good sailing guide to read up on the suggested anchorages. Many people will likely have been there before and written about where they have found good, and where they have struggled. Go and find your own anchorage too, but charts and sailing guides are a great start
- Swell: Far more than wind, we are looking at swell. Unless you have a big fat catamaran (In which case we’ll be the ones looking at you jealously – catamarans are a joy at anchor) then even a little swell from the wrong direction can cause you to have an uncomfortable night. Gauging this is a mixture of luck and experience, but the more open the anchorage is, the more you risk a rolly night. We love a little basin or a hidden-away nook. Look for natural wave breaks, such as islands, reefs, or headlands, that can shield your yacht from the waves.
- Mark your ideal spot: Especially in a tight anchorage, we will always use a flag or other marker on our electronic charts to guide us to exactly where we need to be in our anchorage location. The eye plays tricks on you and a shore or rocks can seem impossibly close when approaching. Knowing that you are 100 metres off and in safe water is a blessing. Knowing also that once your desired rode length is deployed you still have a safe margin behind you is also key. Again, it can seem very, very close to the naked eye. Proper preparation will allow you to be in the right spot, the first time.
- Crowded anchorage. If you are coming into a crowded anchorage (as you often will on a charter boat) then the number one advice is to get there early! Trying to eke out space amongst 30-40 yachts is stressful and sometimes dangerous. The risks are twofold. First, will you cross anchors and end up with a tangled chain. Second, once you have motored backwards and dug in your anchor, will you be left with enough swinging room in relation to the other yachts? The quick answer is to gauge where a nearby yacht has dropped its anchor and attempt to drop in the same place, but 30 metres or so to one side.
Preparing Your Equipment
At Rubicon 3, we are fastidious in our preparation before anchoring. If you’re coming into a big open bay in daylight, then you can maybe afford for things not to go right the first time and to come around for a second go. In contrast, we are often anchoring in tight spaces, in strong wind and fading light after a full day of expedition sailing. We simply cannot afford for anything to go wrong. This is our checklist.
- Check the anchor is securely attached: It sounds silly, but it’s not as silly as dropping your anchor only to find it is not attached securely to the rode or the rode is not attached to the boat at the bitter end. You won’t need to check every time if you are anchoring regularly, but check at least once a season.
- Check the windlass is free to drop: You should be free dropping your anchor, not lowering it on the windlass motor. Once you are in the right place, you want that anchor down and digging in, not slowly being lowered. Also, why use the motor when gravity does the job for you? However, a free drop does necessitate a free windlass clutch. With the anchor tied to the boat and secure, break open the clutch and the re-tighten hand tight. This will ensure when you come to free drop, you can be confident that the chain will run free.
- Hang the anchor over the bow roller: Before we enter the anchorage, we want our anchor to be on the anchor rollers but angled down about 45° over the front of the boat. This ensures that is it still totally secure and cannot damage the boat by swinging around, but that as soon as we are ready to anchor, we can pull the trip line (usually a sail tie), open the windlass clutch, and know that the anchor will drop.
- Flake the anchor chain: Most anchor chains are located in the very forward part of the yacht – which is a nightmare. A bouncy passage means that the chain is bouncing up and down and tying itself in knots. It is so easy, and so common, for this to happen and it can lead to a dangerous situation where your chain is half down but cannot go further. If we have any suspicion that this could have happened, we will open the anchor locker and flake the chain by hand. It is messy and hard work but it is essential and often marks a pro out from an amateur.
The Anchoring Process: Step-by-Step
- Gentle approach. Get your sails down in good time and make sure everything is squared away. Approach slowly, using your depth sounder to monitor the water depth and get a really good visual fix on landmarks and navigation aids so that you are comfortable with where you are. If you have Navionics on your phone (and if not, why not?) then you can guide yourself into your exact spot.
- Ensure you are downwind or down tide. Remember, tide nearly always takes preference over wind, but whichever one is the dominant force for your location, ensure you are motoring into it, maximising your control and ensuring you will move back from your anchor drop location, not over it.
Dropping the Anchor
- First drop. Once you’ve brought the boat to a stop, it’s time to drop anchor, controlling the speed with the clutch or brake. You want the anchor down quickly but not so fast that you lose control of the chain or cannot see how much has gone out (you must have depth markers. We use the RYBWG – Red Yellow Blue White Green marking system to mark every ten meters)
- Stop the drop. Once the anchor has hit the floor, plus a little more, you need to stop any more rode coming out. If you don’t, you will end up with a pile of chain and risk an underwater tangle. The bow should stop blowing off by this point.
- Ease out the rode. Now gently ease out the rode, as the boat drifts back off the wind or current. Judge the speed to ease out the rode by the actions of the boat. You do not want it swinging wildly or blowing too far off the wind. You want to keep the yacht roughly in its anchoring profile and just be moving slowly backward in the opposite direction to which it will be facing once settled. If there is not sufficient wind or tide, you can motor back very gently using the engine.
- Payout c. 5:1 rode to depth. How much line to use is partly a formula and partly experience. Rode length should be between 4 and 7:1 the depth of the water. So if you are in 50 feet of water, you will want about 250 feet of rode. Less than 4 x depth and the rode will pull the anchor’s shaft up and risk dislodging it from the bottom. More than 7 and you are just adding weight (which could be a positive). Ideally, you have a mixture of chain and rope rode, with the chain at the anchor end. The chain is key for weight and to reduce swinging, but the extra rope will allow you to anchor in much greater depth.
- Test the hold. You may find the anchor drags at first, but once the anchor holds you will see the rode come tight. You’ll see this visually, but you can and should also put your hand on the rode and feel for any vibration. If it doesn’t find a hold, you’ll need to pull it back up, reset and go again. If after three goes it doesn’t hold, you need to move a good distance away before you try again. Once you think it’s held, apply a little astern on the engine to ensure the anchor is dug in and not dragging.
Post anchor protocols
- Anchor symbols. Once you’re happy that you’re securely anchored, get that anchor ball up and before it gets dark, switch your anchor light on (This is one all-around white light). You are almost certainly not insured if you don’t have the ball and light, so don’t be lazy!
- Set a snubbing line. You do not want the anchor rode snatching and producing shock loads on the windlass. Once you are happy, tie a mooring line around the rode using a rolling hitch and secure it to a bow cleat. Then ease out the rode until the snubbing line has the load. This stretch line will make for a much more comfortable night.
- Take bearings. Take a couple of bearings on clear reference points, so that if you are concerned during the night you can quickly check whether you have dragged or not.
- Set the drag alarm. Most GPS systems these days have an anchor drag alarm, so set this and give yourself extra peace of mind.
Further Anchoring Techniques
Using a second anchor can provide significant benefits in various situations, particularly when anchoring in challenging conditions or when seeking better stability. You may think about using two anchors in the following scenarios
- Tight Anchorages: When anchoring in confined spaces or areas with limited swing room, using two anchors can help to spread the anchor’s holding power and prevent the yacht from swinging into obstacles or other boats. You may well need to use this technique in narrow channels or anchorages with limited swinging room.
- Strong Currents: In areas with strong currents, using two anchors can provide better resistance to drag and reduce the risk of the anchor dragging across the bottom. This is because the two anchors, when set in opposing directions, can work together to counteract the force of the current.
- Poor Holding Bottoms or Strong Currents: When anchoring in soft, muddy, or sandy bottoms, or in very strong currents, using a second anchor can increase the overall holding power of the system. This is because each anchor can dig in and provide a firm grip on the bottom.
- Roll Reduction: When anchoring in a rolly bay, you can use a second anchor to help keep the bow of the boat more into the waves, thus reducing the roll that can make the anchorage very unpleasant.
- Storm Anchoring for Increased Security: During high winds or other periods of severe weather, using two anchors can provide additional security and may prevent the yacht from dragging or dragging the anchor. The combined holding power of the two anchors can be significant, but they have to be set right.
- If you do use two anchors, you will need to set one first, then motor forward at about a 40° angle, drop the second and repeat the process. The windward anchor should be the second anchor set, as this will help to counteract the force of the wind and prevent the yacht from swinging. The first anchor, which is typically set slightly further forward, will help to maintain the yacht’s position and provide additional stability.
Retrieving Your Anchor: Weighing Anchor Safely
In benign conditions, weighing anchor is straightforward. However, add in strong wind, current or both and it can become a difficult manoeuvre that needs to be conducted with skill and precision.
You will need to have someone at the helm, controlling the speed and direction of the yacht. You will also have someone else at the bow and stern technique, operating the windlass. Ideally, you would also have a third crew member, who can help the helm see exactly where the anchor rode is and which way the yacht needs to move.
- Now it’s time to get the anchor up. You want the anchor rode to be pointing almost horizontally down so that the windlass is hauling up the weight of the anchor, not pulling the yacht toward the anchor. To achieve this, the signaller at the bow must direct the helmsman to move the yacht in such a way that the load is only vertical.
- We use a set of hand signals that makes it very clear what the helmsman needs to do. A chopping motion signals for the helm to move the boat in that direction. A raised first means stop the boat. When the anchor rode is near to the bow, the outstretched arm is used to show the angle and direction of the rode. It’s a simple set of signals but it works well.
- As soon as the rode is vertical, the windlass is operated to bring the chain up. If it’s dirty, use buckets of water and a brush or a hose to wash it off as it comes up.
- If the rode becomes angled again and under load, hold the windlass and allow the helm to bring the yacht back into position before recommencing.
- Once the anchor is off the bottom (You will know this by the easier running of the windlass and by the rode now going straight down) signal to the helm with the palm down and a swinging motion of the arm. It is key that they know this, as the yacht is now free and must be controlled solely by the engine.
- If the anchor is very dirty, you may wish to leave it just under the surface as the yacht motors gently forward, forcing the mud or clay off it.
- Now you need to bring the anchor up quickly. You do not want it swinging into the hull of the yacht. If it is rotating, try to time it so the flukes are facing down just as it arrives on the bow roller. You may need to use a deck brush to push it around if it is not playing ball.
- Once it is fully up, ensure it is well secured and the windlass is switched off. You are free to set sail!
Maintaining Your Anchoring Equipment
It is all too easy to ignore your anchoring equipment and just hope and presume that it will work when it comes time to need it. That, however, is a recipe for failure and poor seamanship. Both during the off-season and the season itself, there are checks and maintenance protocols that need to be followed.
Once your boat has finished its work for the season, pull the boat anchor, chain rode, rope and other anchoring gear out and give it a good wash and inspection. You need to look for damaged links in the chain and chafe to the rope. Check that the swivel is in good working order and that the shackle is secure, the pin well moused and the chain attached securely to the anchor. It’s also a rare opportunity to ensure the bitter end is still securely attached to the boat! Wash out the locker and if necessary remark the chain, using zip ties, markers or the paint scheme we describe above. Next, you want to service your windlass, which will likely involve checking the oil level, cleaning the clutch, brake and cones and ensuring the battery terminals are clean, greased and secure.
Feeling confident in the use of an anchor is such an essential part of cruising, that it has to be in the toolbox of every skipper or you will greatly limit your range and experiences. Ensure you have a good anchor using the knowledge and guidelines we have given you here, and follow the techniques for dropping and retrieving the anchor. Start somewhere safe and accessible with benign conditions, and as your skills and experience increase you can start to anchor in more adventurous and challenging locations.
Frequently Asked Questions
How do I know if my anchor is set?
This is a question that can be difficult to answer definitively. However, some general signs can indicate that your anchor is set.
- The anchor line is taut. If the line is tight and there is no give, this is a good sign that the anchor is dug into the bottom. It is normal that the boat swings in the wind or current, so don’t be concerned about that.
- The rode is not vibrating. Put your hand on the rode. You will almost certainly feel vibrations through it if it is dragging.
- Bearings to key reference points are not changing. Check with your hand-bearing compass, to ensure that you are not moving backwards.
What is the formula for determining the length of the anchor rode?
To determine how much anchor rope or chain is needed the formula is no less than 4:1 and if the wind or current is strong then we will go up to 7:1.
In tidal water, how do I determine a safe depth in which to anchor?
Use FUD. How much will the depth fall between the time you anchor and low tide? How much depth do you wish to leave under the keel? What is the draught of the vessel? Add these together and that tells you the minimum depth in which you can anchor.
Should I always use a snubber line?
Yes! They prevent the shock load that will make for a very unpleasant night and cause considerable wear and tear on your equipment. Use a rolling hitch and let the rope take the strain.