Advanced Anchoring Techniques: Setting and Retrieving in Sand, Mud & Grass

Ever woken up at anchor and realized your boat isn’t where you left it? That sinking feeling (haha sorry) can ruin a night. Whether you're settling in for the evening or waiting out shifting weather, anchoring holds everything together.

When you sail offshore, you need to know how to hold position. Wind shifts, swells roll in, and the seabed isn’t always predictable. If your anchor setup doesn't suit the bottom, you risk dragging or resetting in the dark.

In this article, you’ll learn how to choose anchors for different seabeds. You’ll also learn how to calculate scope, set your anchor securely, and recover it cleanly.

How to Choose the Right Anchor for Every Seabed

Anchoring techniques only work when the anchor matches the seabed. Sand, mud, and grass each need a different approach. You can’t expect one anchor to perform equally in all conditions.

Anchoring in Sand

Sand generally often offers the best conditions for anchoring. Anchors like the Rocna, Delta, Mantus, and Spade hold well in firm sand. These scoop-style anchors dig in deep and settle fast.

Claw anchors also perform reliably in sand. For longer stays, especially overnight, pair your anchor with an all-chain rode to increase holding power.

Anchoring in Mud

Mud is less reliable. Its low density makes it harder for your anchor to grip. Wide-fluke anchors like the Fortress or Danforth are better choices in soft mud.

Adjusting the fluke angle to 45 degrees helps the anchor sink deeper. That can improve holding power by reaching firmer layers under the soft surface.

In deeper mud, adding a kellet can help reduce vertical pull (...a kellet, also known as an anchor angel, sentinel, or buddy, is just a weight attached to an anchor rode). This makes the anchor set more effectively by keeping the angle of force low.

Anchoring in Grass or Weeds

Grass beds are tricky. The roots and vegetation block anchors from reaching the seabed. Some anchors bounce or skate across the top without ever setting. We have had to abort anchoring in a given spot on several occasions because of weeds not allowing our anchor to set.

Plow-style anchors like the CQR and Delta cut through weeds better than flat-fluke options. Heavier anchors can help break through the surface and improve your boat’s performance while anchored.

If the anchor drags, shift your position and try again. Sometimes the first drop won’t set, even with the best gear.

A grapnel anchor may work for short stops in light weed cover. It’s not ideal for overnight anchoring due to low holding power.

Anchor Size and Holding Power

Holding power depends on more than just anchor type. Seabed, wind, and anchoring load all affect how well an anchor holds. For safety, size up your primary anchor based on the strongest expected conditions.

Soft mud may cut your anchor’s holding power in half. Plan for that drop and size your ground tackle accordingly. Anchoring in a crowded anchorage adds pressure to get it right the first time.

Scope Ratios: The Numbers That Keep Your Anchor Holding

Once you’ve picked the anchor, the next step is scope. Scope is the ratio between your anchor rode (ie. how much you put out) and the depth below your bow. Get that ratio wrong, and even the best anchor may not hold.

Scope affects the angle of pull. A low angle keeps the anchor buried. A steep angle can lift the shank and cause dragging.

So, how do you figure it out? Start with the water depth beneath you. Add your bow height. Then multiply that total by the scope ratio.

If you want a pro tip from James: “More is more.” Meaning if you can drop more anchor chain, you get better results. Each chain rung acts like a mini-anchor, due to its friction on the bottom. The limiting factor is normally your swing to other boats.

The American Sailing Association has a 7:1 ratio, meaning if the depth plus your freeboard is 10’, you need 70’ of rode to let out. 

Sometimes this is not practicable.

Use these common scope ratios as a guide:

• Calm conditions: Use a 3 to 1 scope. For every meter of total depth and bow height, pay out three meters of rode. This is a bare minimum. You’ll need an anchor watch for this.
• Overnight or unsettled weather: Use a 5 to 1 scope. This gives your anchor a stronger hold and more room to absorb movement. This is pretty typical.
• Storms or rough anchorage: Go up to 7 to 1 or more. This shallow angle increases holding power and keeps the boat stable. This (or even higher) is a great ratio. 

You Can Make Small Adjustments Too

Always calculate scope based on high tide, not low. If the tide rises overnight, your scope shortens unless you let out more rode.

In soft mud or thick grass, increase your scope. These bottoms resist less, so the anchor needs a lower pull angle to stay buried.

In a crowded anchorage, you might need to reduce the scope to stay clear of nearby boats. If so, use an anchor alarm and check your swing often.

You might want to set your secondary anchor at an angle that minimizes your swing. This is something Sailing Virgins have done many times. 

How to Set Your Anchor So It Holds

Once you’ve chosen the anchor and measured your scope, it’s time to set it. This step locks everything in place. If the anchor doesn’t dig in, you’ll drift.

1. Approach Slowly and Stay in Control

Motor into the wind or current at low speed. Stop the boat before you reach your drop point. That pause helps you stay aligned as you lower the anchor. 

Lower the anchor by hand or windlass. Let gravity do the work so the chain or rope drops without piling.

2. Let the Rode Settle and Begin the Set

Let out two to three times the depth to start. Keep the boat in reverse at a gentle pace. This lays the rode across the seabed without jerking the anchor. 

Then let out the rest of your rode based on your scope ratio. Once it’s all out, snub the line to take the pressure off the windlass. That short pause gives the anchor time to dig in.

3. Back Down and Test the Set

Apply reverse power slowly. Start light, then increase throttle smoothly, like a volume control knob over 60 seconds. Watch your position using transits (ie, shore markers) or GPS. 

If the boat holds steady, back down again slightly harder. That second pull buries the anchor deeper and helps lock in the set. Be patient when testing. 

Oftentimes, when you are tired, you want to be convinced that it has set, but it might not have. 

4. Adjust for Seabed Type

In soft mud, wait before applying full power. Give the anchor a chance to sink into the softer top layer. Too much reverse too soon may lift it instead.

In grass, the anchor may skip across the surface. If you slide or drag, pull it up and try again in a nearby spot. Sometimes, one anchor drop isn’t enough. 

Sometimes three anchor drops aren't enough. Don’t stop anchoring until you are very happy, or you will pay a price. 

5. Do Final Checks 

Look at your swing using visual bearings or GPS. Set an anchor alarm if you’re staying overnight. If your boat moves off the original line, you may need to reset.

How to Retrieve Your Anchor Easily

You’ve anchored, set, and held your position. Now it’s time to bring the anchor back up. Retrieval should be smooth and safe, but many sailors rush it and damage gear in the process.

Prepare the Boat and Crew

Before you start, clear the deck. Coil loose lines, secure gear, and get one person ready at the bow. Communication matters during retrieval, especially in wind or chop.

Move the boat directly above the anchor using gentle bursts of throttle. Your goal is to pull the rode straight up, not at an angle.

Use the Boat’s Weight to Break the Set

Stop above the anchor and wait. The vertical pull will begin to loosen the anchor without stressing the windlass. Let the boat do the driving work.

If the anchor still holds, apply light reverse, then forward throttle. Short movements often help break suction without force.

Avoid jerking the line or pulling hard at an angle. That kind of movement can damage the windlass, roller, or deck hardware.

Bring the Anchor Up Steadily

Once it breaks free, retrieve the anchor slowly. Use steady pressure to avoid swinging or damaging the hull. If the anchor spins, use a swivel to reduce line twist.

As it nears the bow, check that the shank is clear. Clean off mud, grass, or debris before stowing it. A clogged anchor can make the next set harder.

Do This When The Anchors Get Stuck

Sometimes, the anchor won’t budge. In sand or mud, try waiting a moment and pulling again. If that fails, motor gently forward, then reverse.

If the anchor remains stuck, try using a trip line. These lines, tied to the base of the shank, can reverse the pull direction. If you are a free diver, this is your time to shine.  In extreme cases, call for a tow or local help. Don’t risk injury or damage by forcing it.

Learn Advanced Anchoring Techniques With Sailing Virgins

You can only learn so much by reading. To get better at anchoring, you need to practice it on the water. Every drop, every retrieval, every change in wind teaches you something new.

Sailing Virgins offers hands-on courses where you anchor in real conditions, troubleshoot in motion, and work as a crew. You’ll earn certifications while building skills you’ll actually use.

• Advanced Sailing Courses: Earn ASA 105 and 106 on a catamaran or monohull. Add ASA 114 if you're on a cat and haven’t completed it yet.
• Offshore Sailing Courses: Sail long passages using a watch system. Gain nautical miles, apply anchoring techniques, and complete ASA 105 or 114 if eligible.
• Private Group Courses: Perfect for friends, families, or special occasions. Available year-round in the BVI, Croatia, and Tahiti. Learn together while earning ASA certifications.

Want to train in some of the best locations on the water? Visit Sailing Virgins to explore course dates, locations, and booking options.