Are you a new boat owner? We’re sure you’re learning a lot about all the different nuances involved with boating.
From driving and navigating the waters to understanding basic maintenance, there’s plenty for newbie boat enthusiasts to understand, and you never really stop learning throughout your experience as a boat owner.
When you’re out at sea, you might find a spot where you want to stop and fish a reef. Likewise, you could be on the river, and you want to stop to admire the sunset.
These occasions call for effective anchoring of your boat. Anchoring is a skill in itself, and it takes boat owners a few attempts to learn how to anchor their vessel successfully.
Anchors are essential pieces of equipment for any boat. This brief guide teaches you everything you need to know about how to anchor a vessel.
Contents
Preparing to Anchor
Before you get ready to drop anchor, it’s a good idea to check the rode. Make sure it’s free of knots and tangles that prevent the smooth running and collection of the anchor. Mark out the length of the rode in specific sections.
The bottom of the rode attaching to the anchor should feature between four and seven feet of chain to weigh down the rode and allow for the effective hooking of the anchor to the seafloor or river bottom.
When you’re ready to set the anchor, make sure the engines are not in operation, and the boat is only drifting in the current. Never toss the anchor overboard when the vessel is in motion.
The forward motion may knock the anchor line against the vessel’s stern, especially in boats with a plumb bow.
Forward movement may also cause the vessel to run over the anchor rode, fouling the keel, rudder system, and props. The boat may also run over the rode, cutting the anchor away while coiling the rode around the props in a tangled mess.
What are the Common Types of Anchors?
Danforth Anchor
A great all-around lightweight anchor. It provides excellent holding power in mud and sand bottoms. Requires some attention when setting on rocky bottoms.
Plow Anchor
The preferred anchor for recreational boaters. You get all-around holding performance in various conditions, from mud and sand to grass and weeds. However, it’s not a good choice for rocky bottoms or reefs.
The Mushroom Anchor
This anchor model sets easily in sand and mud, but inexperienc4ed boaters may have some issues retrieving the mushroom anchor. It’s a good choice for anchoring to mooring buoys.
The Claw or Bruce Anchor
This anchor model is a good choice for offshore use. The original design was for offshore gas and oil drilling rigs, and many manufactures adopted the tech to recreational boats for offshore anchoring.
This model is the traditional choice for anchoring boats. However, it’s usually challenging to stow these anchors away on board. However, you get excellent all-around performance from this anchor type.
The Grapnel Anchor
This anchor comes with a compact design making it easy to stow on boats with minimal deck space. However, the flukes on this model are not as strong as others mentioned above.
Testing Different Anchor Types
Fortress Marine Anchors conducted an in-water test of 11 different anchor models to determine the holding power of each anchor model in a soft mud bottom. The anchors were attached to a research vessel owned by the University of Maryland Center for Environmental Science.
The results of the test show the following.
Anchors with the sharpest flukes provide the fastest set to the bottom.
Most anchors couldn’t offer more than 700-lbs of holding power, regardless of the manufacturer’s claims.
Danforth and Fortress models, featuring wide and long flukes, did better than the plow and claw anchor designs when it comes to holding power in soft mud bottoms. What’s interesting is that despite the innovation in anchor design over recent decades, new-generation anchors offered no additional holding power over traditional models.
The ULTRA and Mantus brands are the only next-generation anchor brands offering more than 700-lbs of holding power. The Fortress FX-37 showed the best performance, offering over 1,000-lbs of holding power, with one of the test sets showing 2,000-lbs of holding power from its anchor.
Like most real-world anchoring scenarios, the test involved three sets, and at least one of the sets offered good holding power. There was at least one occasion during the three sets where the anchor didn’t manage to set to the bottom at all.
The test also shows that when setting the anchor, boat owners should let the anchor settle before they start backing down on it—most anchors require between 10-feet to 20-feet of drag before achieving a firm set of up to 300-lbs.
- Penetrates deep in a variety of seafloor compositions
- Slip ring shank makes it simple to retrieve stuck anchor
- Recommended for boats 20-24 feet in length
- Fluke Length: 9-7/8 inch
- Stock Width: 14-9/16 inch
- Impressive holding power in a variety of bottom compositions
- One piece design with large eyelet and includes a galvanized anchor shackle
- Cast iron construction
- Durable black vinyl coating
- Weight: 20 pounds
- Wide flukes are suitable for a variety of seafloor compositions
- Excellent weight to holding power ratio
- Recommended for boats 25-30 feet in length
- Fluke Length: 14-1/16 inch
- Stock Width: 24-7/16 inch
Dropping the Anchor
When you find a spot where you want to drop anchor, keep in mind that the anchor will drag a short distance of 10-feet to 20-feet or a bit more before it sets. As the boat drifts, lower your anchor to the bottom in a controlled manner, gently playing out the rode to stop the chain from piling up.
If the rode and anchor play out in a single line without any tangles, the anchor should be set to the bottom without any complications. You also have the option of taking a turn around a cleat to take the pressure off of the windlass when letting out the rode.
What Is a Penny Rode Marker?
Measure the anchor rode in sections of 25-feet, two at 50-feet, three at 75-feet, and four at 100-feet. Attach one cable tie in each section as a visual guide to anchor depth.
You can keep going with this system for any length of rode. These indicators let you know the length of rode to run out when you reach your fishing or dive spot and the depth to the seafloor.
Laying Out the Right Scope
The anchor will secure property to the bottom when a horizontal load applies to it. So, you’ll need to let out enough scope to achieve effective anchoring. To estimate the right scope, you’ll have to make a calculation.
Add the water depth to the height of the bow from the water level, and multiply that figure by 5. Payout that length of rode to give you the “lunch-hook.” Make sure you are aboard, awake, and watching the ocean or river conditions.
If you’re at sea and the tide is pushing in, adjust the scope to 5-to-1 scope when it’s fully in. If the conditions are windy, it’s a good idea to increase the scope to a 7:1 ratio. If you’re spending the night out on the water, we recommend increasing the scope to an 8:1 ratio.
Important Note:
Remember to exclude the chain from your measurements and calculations when calculating scope. The chain’s job is to weigh down the anchor and settle on the seafloor. So, don’t include it in the calculation unless you have a chain length of over 6-feet.
Depending on wind strength and time at anchor, here are scope recommendations for mixed rope and chain rode setups.
Larger boats anchoring overnight require two to four boat-lengths of chain attached to the rode. So, for instance, if you’re anchoring in water 10-feet deep, and you have a bow raised 5-feet over the water-line, then the calculation is as follows.
water depth (10-feet) + bow height (5-feet) = 15-feet.
Therefore, for a lunch hook, you’ll need 75-feet of rode.
Quick Tip
Most adults have arm spans of between five to six feet across. So, you can save time paying out the rode by using your arm span lengths to measure the amount of rode you need for successful anchoring at your site.
Line Vs. Chain Rode
If you’re anchoring in oceanic locations like reefs, rock beds, or over debris, a chain is more durable to the environmental elements than a rode. Chains also dig into soft mud bottoms, providing an ideal anchor setting.
The anchor chain forms a curve, or catenary, in the rode, allowing the anchor to keep pulling in a horizontal fashion, so it sets in the ideal position for the best holding power. All-chain rodes have some catenary in all but the most-intense winds, such as hurricanes.
Choose the Right Anchor Site
When you’re choosing your anchoring site, remember to look for a spot clear of submerged objects and debris.
Check your charts to ensure no nautical cables or obstructions on the seafloor. Next, determine the water depth at the site and calculate the amount of line you need for successful anchoring.
As discussed, the general rule is five times the length of the boat plus the distance from the water line to the top of the bow.
Lower Your Anchor Slowly
When anchoring, run out the rode in a controlled fashion, don’t just let it run away from you until it reaches the bottom.
Throwing the anchor over the vessel’s side tends to foul the line. When lowering the anchor, the boat should be drifting backward slightly. This movement allows the anchor to away and down from the boat without fouling under the hull and keel. The backward movement of the vessel is necessary to prevent the chin or rode from piling up on the seafloor, stopping the effective setting of the anchor.
So, if you’re boat isn’t moving backward, turn on the motor and flip the throttle to get the vessel moving gently in the backward direction when dropping the anchor.
Keep Tension on the Anchor Rode
While you’re dropping anchor, make sure you keep tension on the rode at all times. Keep the bow of the boat pointed towards the anchor at all times.
This strategy ensures your chain, anchor, and rope remain aligned, preventing tangling. When anchoring in strong winds, you might have to put the boat into the forward gear to get an effective anchoring against the current and winds.
Setting the Anchor
After you let out the rode to the right scope for the location, let your boat settle back onto the anchor as the rode straightens out. As mentioned, you can gently move the boat to the rear with the engine if there is no wind or current.
The boat will likely shift astern ever so slightly during the anchoring process as the flukes strike the bottom and start to hold and straighten the line. If the anchor doesn’t set, pick it up and repeat the process in another spot.
If your boat is in a fixed position, you’ll notice that the anchor rode is taut and straight, and you’ll also see prop wash alongside the aft side of the vessel. When the boat stops moving and the line remains straight, you have successfully set your anchor.
Weighing the Anchor
After setting the anchor, you’ll have to retrieve it or “weigh the anchor.” Ensure that you’re wearing your life jacket during this procedure, as it’s a risky situation for falling overboard.
Some smaller boats may find they get swamped due to the combination of weight, current, and anchor pull that draws water into the vessel.
When retrieving your anchor, pull it up gently to release the flukes. If the current is strong, you can maneuver the boat using engine power to get slack on the line.
If your weighing the anchor in mud bottoms, clean the anchor off in the water before dragging it into the boat.
Understanding Anchor Chains
An anchor catenary comes from having the right anchor weight. However, having a heavy anchor aboard may change the boat’s performance, adding more weight to the vessel’s front, slowing its performance and handling response on the water.
Unless you have a large performance boat, or you just feel like cruising, you’re going to need a rode comprised mainly of rope connected to a smaller length of chain.
Nylon line offers you the best choice for your anchor rode, providing stretchable characteristics while providing excellent tensile strength to avoid snapping off the line under large loads. We recommend looking for rope consisting of a three-strand nylon design.
The polyester line is another good choice and resistant to chaffing on the boat hull. It’s 15% stronger than nylon, but you don’t get the same elasticity and resilience in the line that you do with three-ply nylon. You can get away with three to four lengths when it comes to chain, but the more, the merrier.
It’s important for boat owners to note that using a rope/chain hybrid rode is only compatible with specific windlass designs. Most windlass models will require you to use a chain-to-rope splice, requiring more maintenance to check for chafe.
Use a good quality shackle to create an effective rode and tie the anchor system together. Remember to mouse the pin to stop it unscrewing.
Rigging a Snubber
A snubbing line or anchor snubber has two key functions for those vessels using all-chain rodes. Absorbing shock from the pulling action on the chain rode is critical to prevent to overloading of the anchor windlass.
Boat owners can use the snubbing line set up to reduce this shock from the pulling effect from the rise and fall of the ocean. The anchor chain provides slack between the windlass and the rode, reducing the shock on the windlass system.
The easiest way to rig a snubbing line is to attach a 20-foot nylon line to the rode or chain using a rolling hitch. Do this after setting the anchor and before deploying your final length of chain. Attach the end of the snubber to a sturdy bow cleat and feed out more of the rode or chain until it has a lo0ose nag between the windlass and the rolling hitch.
The snubber takes all the weight off the line when you rig it correctly, reducing pressure on the windlass. Letting the chain loop between the cleat and the rolling hitch will add more weight. As a result, this action increases the catenary effect, improving the holding power of your anchor while giving the rode additional shock absorption characteristics.
For even faster rigging of the snubber, boaters can invest in a chain hook or snubbing hook for their all-chain rode. Both options come in different sizes to suit chain lengths and sizes, and they feature permanent splicing into the end of the snubbing line.
After successfully anchoring the vessel, slip the chain hook over the chain link, and attach the snubber to the boat. Let out a little more chain until the snubber gets taut.
Wrapping Up – A Few Additional Anchoring Tips
One of the dangers of anchoring is swamping your boat. We’ll leave you with a few more tips for the effective anchoring of your vessel without presenting a sinking risk.
- Don’t tie off your anchor to the stern of the vessel.
- Don’t attempt to use the engine to retrieve a stuck anchor.
- If you can’t release the stuck anchor, it’s better to cut the line and let it go than risk swamping your boat.
