How to Anchor a Boat
Anchoring a boat is one of the most important steps to ensuring safety on the water. If you haven’t mastered this step you can put yourself and your passengers in danger. Not to mention your boat and other vessels as well. If you plan to weigh anchor, follow our guide to ensure it’s done right the first time.
It’s important to understand all the parts of the anchor and also which anchor you need as well. Not every anchor works for every boat or every type of bottom.
What is the Anchor Line?
In the simplest terms, in order to anchor a boat you need three things. The boat, the anchor and something to connect the two. You have the boat and soon we’ll discuss anchors. So that thing that connects the boat and the anchor is the line. This is the tether that ensures you stay anchored.
Your anchor line can be a rope or a chain. In many cases it can be a combination of both. But there is something important you need to be aware of and that is the anchor rode.
What is an Anchor Rode?
Whenever possible you want to use correct terminology when boating. So while anchor line is not incorrect, the proper term is rode. The anchor rode is the anchor line. People may also call it the anchor rope. But they’re all the same thing. For our purposes, we’ll stick to calling it an anchor rode. It’s the right way to refer to it and it’s a good habit to get into.
When you let out your anchor rode, that length is called the scope. Think of it like telescoping. It goes out and then gets pulled back. This is important to know. You’ll need to calculate how much rode to scope depending on conditions.
Choosing the Right Anchor Rode
So what kind of line makes for a good anchor rode? There are several to choose from. Nylon rope is by far the most popular. For small boats, three strand nylon is a good choice. It’s tough and lightweight. They are not ideal when it comes to abrasion resistance. That means if you plan to anchor near coral, you might need something stronger. If coral rubs on three strand nylon for a while, it will cut right through. That said, for smaller vessels or most winches, it’s a good choice.
An all chain rode could be used as well. These obviously have no issue with chafing and abrasion. They can be reeled in with a windlass and they are strong. The weight of the chain itself means you don’t need a long scope. But you need to be aware of the downsides. With no elasticity, chain can pull extremely and dangerously tight. A nylon line called a snubber can help prevent this.
The other real downside to all chain is weight. Depending on your boat, a chain and windlass combination can add a few hundred pounds to your boat. That can really alter your performance. Not to mention the fact that chain can get pricey.
Rope and chain combination rodes help fight the abrasion issue. A length of chain, typically between 6 feet and 30 feet can prevent abrasion cuts. If your boat is under 30 feet, use a length of chain that equals one boat length in total. There is usually a shackle that connects the rope to the chain. This is a potential weak point if you lose the pin that holds it together
There are spliced versions of the rope and chain combination. They don’t use that shackle. That means you can use this with a windlass. We think a combination of rope and chain is hands down the best idea for your rode. You can get the best of both worlds without loss of performance.
Fluke Anchors vs Plow Anchors vs Mushroom Anchors and More
Picking the ride kind of anchor rode is one step to properly anchoring your vessel. But you need the right anchor as well. People are are new to boating are often surprised by the wide variety of anchors available. This is in part because everyone has the anchor stereotype in their head. Those navy anchors are an iconic image, after all. It’s even a classic, cliché tattoo. But real life anchors come in a variety of sizes and shapes. A larger anchor is better for larger boats, obviously
Fluke Anchor: These are also sometimes called a Danforth anchor. They’re popular with many boat owners. They have picoting flukes that look like two thick tines on a fork. This is what helps dig into the bottom to anchor you. This kind of anchor works best on a muddy bottom. They’re great in sand as well. The flukes dig in and set well. These are not ideal for a rocky bottom, however.
Plow Anchors: A plow anchor gets its name because it resembles a plow you’d use in a field. It’s an almost spade shape that lands on its side when it hits bottom. The plot part pulls and then buries itself. It’s ideal for rocky bottoms. It can also set well in a bottom with a lot of weeds.
Mushroom Anchors: You’ll want to use a mushroom anchor on a flat bottom. They don’t set the way other anchors do. And they’re not ideal for bigger boats. However, if you’re fishing in a canoe or a kayak? This could be a good choice. They’re best for a loose bottom that they can settle into.
Another time when you might use a mushroom anchor is for a permanent mooring. That means something like an anchor buoy. In these cases, a mushroom buoy is incredibly powerful. The reason is that, over time, silt builds up on them. They essentially get buried by the current. Once buried, they can be many times stronger than other anchors. But for casual boating? These are not ideal.
Claw Anchors: Many of these come with roll bars to help reset. They have a single point design, similar in many ways to plow anchors. They set well in many rough and rocky surfaces. Coral and weeds are also ideal for these. They are also good at resetting when they come loose. These are not great on softer surfaces though. Stick to rocks but not mud and sand with a claw anchor.
Grapnel Anchors: These anchors look like grappling hooks you might see in movies. Typically they have four spikes on them. These are typically best for smaller vessels. A small fishing boat or even a dinghy can make good use of these. The grapnel will anchor to a rock and sets incredibly strongly. Then you can fish until you’re done and pull it up easily.
What Anchor Material is Best?
Anchors are typically available in several materials. You’re likely going to be looking at anchors made of aluminum, stainless steel or galvanized steel. There are others out there, like titanium, but those can cost thousands.
Aluminum Anchors: These are lightweight anchors which makes them ideal for storage on a boat. They are also corrosion resistant. They can be very strong and have good holding ability. The big downside to an aluminum anchor is often the price. These can cost more than steel. Also, they’re not actually as strong as steel.
Stainless Steel Anchors: Stainless is a super tough metal. And, brand new, these look amazing. But remember, an anchor is under water most of the time so who cares what it looks like. We only say that because these can be very pricey as well. And that shiny, stainless appearance wears off pretty quickly with scrapes and bumps.
Galvanized Steel Anchor: These anchors are tough and relatively cheap. If you want a good, reliable anchor and don’t want to pay a lot, galvanized is your friend. They have good holding power and a good weight. But you need to keep a couple things in mind. One, these are less attractive than stainless and aluminum. And two, the galvanization can wear off. If that happens, they can and will start to corrode. The good thing is you can always regalvanize an anchor if you need to. Just keep in mind they may start to rust over time. So always make sure you inspect your galvanized anchor just in case.
Overall, any one of these metals is great. But for a mix of cost efficiency and reliability, we recommend galvanized. If money isn’t an issue, try stainless.
How to Drop Anchor
Now that you have a rode and an anchor you have what is known as your ground tackle. This is what you need to stay well rooted. But it’s still not as simple as just throwing an anchor in the water. Let’s walk through the steps necessary to anchor your boat properly.
- Select an area that offers maximum shelter from wind, current, boat traffic etc.
- Pick a spot with swinging room in all directions. Should the wind change, your boat swings bow to the wind or current, whichever is stronger. We’ll cover this issue later in what to do about dragging. You can prevent wind, but you can prepare for it.
- Determine depth and bottom conditions and calculate how much anchor line you will put out. Remember to keep the tide in mind if that’s an issue where you are. There are several ways to calculate this. But for many people, seven times the water depth plus the boat’s freeboard is ideal.
- If other boats are anchored in the area, ask the boat adjacent to the spot you select what scope they have out. That way you can anchor in such a manner that you will not bump into the neighboring vessel.
- Anchor with the same method used by nearby boats. If they are anchored bow and stern, you should too. If they are anchored with a single anchor from the bow, do not anchor bow and stern. Never anchor from the stern alone, this could cause the boat to swamp or capsize.
- Rig the anchor and rode. Check shackles to make sure they are secured with wire tied to prevent the screw shaft from opening.
- Lay out the amount of rode you will need on deck. Do it in such a manner that it will follow the anchor into the water smoothly without tangling.
- Cleat off the anchor line at the point you want it to stop. (Don’t forget or you’ll be diving for your anchor.)
- Stop your boat and lower your anchor until it lies on the bottom. This should be done up-wind or up-current from the spot you have selected. Slowly start to motor back, letting out the anchor rode. Backing down slowly will assure that the anchor chain will not foul the anchor. That means it won’t prevent it from digging into the bottom.
- When all the anchor line has been let out, back down on the anchor with engine in idle reverse to help set the anchor. (Be careful not to get the anchor line caught in your prop.)
- While reversing on a set anchor, keep a hand on the anchor line. A dragging anchor will telegraph itself as it bumps along the bottom. An anchor that is set will not shake the line.
- When the anchor is firmly set, look around for reference points in relation to the boat. You can sight over your compass to get the bearing of two different fixed points. Look for things like house, rock, etc. Over the next hour or so, make sure those reference points are in the same place. If not you’re probably dragging anchor.
- Begin anchor watch. Everyone should check occasionally to make sure you’re not drifting.
- Retrieve the anchor by pulling or powering forward slowly. Do this until the anchor rode hangs vertically at the bow.
- Cleat the line as the boat moves slowly past the vertical. This will use the weight of the boat to free the anchor and protect you from being dragged over the bow.
- Once free, raise the anchor to the waterline.
- Clean if necessary and let the rode dry before stowing away.
How to Avoid Wind Dragging
There’s a real way to anchor safely. As we’ve seen, there’s real science behind this. And if you do it wrong, there can be consequences. More than one boater has dropped anchor for the night and awoken confused. The boat is no longer where they left it and is now dangerously close to rocks or another boat. And that’s if you’re lucky. Running into those rocks or a boat is a real possibility.
Equally terrifying is anchoring your boat and heading ashore for a while. You come back and the boat isn’t there. Panic sets in pretty quick. Was it stolen, or is it just adrift? Before you call the police and the Coast Guard, check the area in case your boat was dragged away.
The fact is, winds and currents work against you and your anchor. You need to be aware that most anchors are not infallible. Even if you bought the best, most expensive anchor on the market.
If the anchor doesn’t set exactly right, that’s a recipe for disaster. And it can happen easily. You’ll never know it until it’s too late, typically. Or if it seems set but the bottom is not what you were expecting. Maybe it’s too loose or you’re stuck in rubble. Something that seems firm at first until the winds shift. If the boat drifts and pulls at the anchor from a new angle, it could pull it free. When that happens, if you’re not right there to fix it, your boat can go for quite a trip. And the worst part is that the anchor will still be down there when you catch up with it.
Your best bet for avoiding wind changes is two anchors. You want to set the second anchor in a V-shape. If the wind starts to shift and the boat drags the anchor, the other is right there. Because they are at opposing angles, odds are one will always set even if the other does not.
In extreme cases you can still up the ante. A third anchor can be used as well. The shape is the same, just use a V. In this case, one anchor goes out straight down the middle of the V. You would only use this method in serious weather. If you know a bad storm is coming and you are going to try to wait it out, the three anchor V can help keep you secure.
What About Tight Spaces?
So you want to set your V but there are other boats nearby? Now what? The tightness of your anchorage depends on how much room you have handy. If you have room to turn around and not hit anything at all, then the V we mentioned is fine. The angle can be anywhere from 140 degrees to 180 degrees. That 180 ensures you move less, but you’ll need a big anchor. Your boat can still move with the wind. The bow stays still because of the anchors, but the stern shifts in the wind. If you plan to sleep on your boat, this is a good way to do it. The motion is much less bothersome.
But if you don’t have room, you’ll need more security. You never want to risk hitting another boat. If you’re near other vessels or underwater hazards, another anchor can help you out. Use the V formation off the bow. But also employ another anchor off the stern of the boat. You can do this vice versa as well. Byt that we mean two stern anchors in a V and one at the bow. It depends on how the wind is blowing and what works best.
This three anchor method prevents the boat from drifting around the anchors. Remember, with anchors in a V, your boat can spin around them in a full 360. With a stern anchor, you stay rooted in place. The downside here is that the motion on the boat is really felt. You’re fighting the current and the waves more noticeably. It can make for a rough night of sleep.
What About the Tide?
If you’re not used to boating in tidal waters, it can be tricky. You set the anchor, your boat seems secure. Then the tide rolls in. If you didn’t prepare, you’ll find yourself adrift. Contrary to popular belief, the tide isn’t lifting your anchor off the bottom. Instead, the tide is lifting your boat. That, in turn, alters the angle of the rode. You’ll lose the angle so badly the anchor can’t hold anymore.
One thing you need to remember is that the tide can raise your boat around 3 feet or 1 meter. That’s an average change. But it can be a lot more extreme at some places too. As much as 14 feet. You need extra rode to compensate for this tidal shift. If you aren’t sure how much the tide is going to affect your boat, then just wing it. By that we mean, add at least 20 or 30 feet to the rode.
Always be sure you know the depth of the water you’re anchoring in. This is all fine and good for anchoring at low tide. What happens if you anchor at high tide? If you don’t prepare, you may find yourself in water far too shallow at low tide. Preparation is often the difference between a good trip out on the boat and a disastrous one.
The Bottom Line
When you’re new to boating, a lot of this can sound very confusing. It seems like there’s so much to keep in mind. But remember, it’s a matter of safety so it needs to be done. And if you mess up setting a boat anchor, don’t worry. Try again! Practice makes perfect as they say.
Always make sure you’re using high quality anchors and high quality rode. This is not a place to cut corners. If the boat starts to drift and the anchor comes loose, don’t panic. These things happen. Compensate or adjust as needed.