The Secret to Staying Put: Choosing the Right Anchor Size!

Imagine this. You are out on a beautiful Florida afternoon. The sun feels warm on your face. You drop your hook in a quiet cove to eat lunch. Suddenly, the wind picks up. Your boat starts sliding toward the jagged rocks. Your heart jumps. This scary moment can happen for a number of reasons.  Could be the wrong anchor for the type of bottom.  The bottom could be mud, sand, gravel, reef, grass, etc.  Could be anchor and chain are too light for your boat, could be not enough scope. 

Scope is how much anchor line or chain you let out. For best holding, let out at least a 7:1 scope.  This means let out the anchor line equal to at least 7 times the depth of the water you are anchoring in, assuming you have the room to swing that much, if the wind or current changes direction. 

Could also be something fouled your anchor, for example: I was dragging the anchor once so I pulled up the anchor with the intention of lowering the anchor in a different location. When I got the anchor all the way up, and it was resting on the bow of my boat, I  noticed that the anchor had become entangled in an item of clothing that had been resting on the bottom.  After unwrapping the anchor, I again lowered it into the water, and it dug in just fine; problem solved.  It can help if you “set” the anchor after lowering it.  On boats with an engine, once you have let out your 7:1 Scope, put your engine in reverse and throttle up some to “set” the anchor (help it dig into the bottom). 

If the anchor sets, then your boat should not move even in reverse with the engine throttled up some.  Then turn off the engine.  If your boat has no engine, you can help set your anchor with a couple of sharp pulls on the anchor line.   This can help the anchor dig in.  If the wind or current in the anchorage is pushing your boat back hard, you should not have to set the anchor.  The force of the wind or current pushing back on your boat should be enough to set the anchor.

Choosing the right anchor types for small boats is about more than just a piece of metal. It is your "parking brake" on the water. Many new sailors look at big, heavy ships and think they need something massive. Others think a tiny brick will work. Both are wrong. You need the "Goldilocks" fit.  Not too hot and not too cold.  Just right.

At Rick's Small SailBoats LLC,  we have never heard someone complain that they bought too big of an anchor or too much chain for their boat.  However, the heavier the anchor, the more strength it will take to get it back on board, unless you have an anchor windlass.  If you are not anchoring over night, and just stopping for lunch, you may want a small anchor called a lunch hook.  Save you larger anchor for keeping the boat in one place overnight.

How Big Should Your Anchor Be?

When you look at a trailerable sailboat, weight is everything. You want something light enough to lift by hand. However, it must be able to dig in and hold in the type of bottom where you are anchoring. Most small sailboats between 14 and 22 feet do well with a 4-pound to 8-pound anchor with 3 to 6 feet of chain plus 100 feet of nylon anchor rode.  The type of bottom most prevalent in your sailing area will dictate the design of the anchor you choose.  

● Wind Surface: If your boat has high sides, the wind will push it harder.

● Chain Length: Always use at least six feet of galvanized chain to keep the anchor flat.

According to 2024 maritime safety data from the BoatUS Foundation, nearly 15% of recreational "drift" incidents occur because of improper boat anchor systems. This shows that even a small mistake in gear choice can lead to a big headache on the shoreline.

Boat Length (ft)	Boat Weight (lbs)	Fluke Anchor Weight	Delta/Plow Weight
12 - 16	500 - 1,000	4 lbs	6 lbs
17 - 21	1,000 - 2,500	8 lbs	10 lbs
22 - 25	2,500 - 4,500	13 lbs	14 lbs

How Bottom Type Affects Your Hold?

Which type of bottom is most ideal for anchoring?

The answer is sand.  Use a Danforth-style anchor for Sand and Mud bottom types

Danforth-Style Anchor

Learning to "read" the seabed is a superpower for sailors. If the water is clear, look for light-colored patches—that’s usually sand. Dark, patchy areas often mean seagrass or rocks. Choosing the right metal for the terrain means you won't have to keep pulling the anchor up to reset it. This saves your back and prevents your gear from getting scratched up on rough rocks.

●        Rock and Reef Bottom:  Use a grapnel anchor and a trip line with its own buoy.  The trip line is tied to the opposite end of the anchor from where the anchor chain or nylon rode is tied.  This allows you to pull the anchor out of the rocks backwards.

Grapnel Anchor

●        Grass: The worst bottom type for holding.  Try to find somewhere else to anchor with a different bottom type.  Or, if the water is clear, you may see a sandy area surrounded by grass.  Try to drop the anchor in the sandy area.

●        Hard Gravel bottom:   You need a heavy plow or Bruce-type anchor to penetrate the hard bottom.  Light anchors will just slide along the bottom and never dig in.

The mushroom anchor takes months or years to sink into the bottom.  It is only good in soft sand or mud bottom types.   It is used for mooring buoys once it has settled into the bottom. 

Wait until you see what happens when the tide reverses at midnight... If you are concerned about dragging when the current or wind changes direction, it is good to set up an anchor watch system or a GPS anchor alarm that will alert you to position changes and your dragging anchor.

Mushroom Anchor

Setting Up Your Anchor System, aka Ground Tackle 

Anchoring is a skill we teach in our 8-hour hands-on lessons. It is not just about throwing the metal overboard. You have to "set" it. This means backing up the boat slowly until the line tightens. This pulls the points into the ground. If you just drop it in a pile, it will tangle.

You also need a good "rode." That is just a fancy word for your rope and chain. The chain is the secret sauce. It is heavy and stays on the bottom. This keeps the pull on the anchor horizontal. If you pull upward, the anchor pops out of the mud like a loose tooth.

●        Rope Choice: Use nylon rope because it stretches like a rubber band.

●        The 7:1 Rule: Let out seven feet of rope for every one foot of water depth.

●        Cleat Hitch: Always tie your rope to a strong horn cleat on the deck.

●        Check the Swing: Make sure you aren't going to hit other boats if the wind shifts.

If you are looking for a small boat anchor type, consider the folding Grapnel. It is great for very short stops on rocky bottoms. However, it can get stuck easily. We usually suggest a Danforth style for most of our Florida customers because it works so well in our sandy coastal waters.

Matching the Gear to Your Boat

A light boat doesn't mean you can use a toy. If you wonder which type of anchor for small lightweight boat users should buy, the answer is often a Danforth-style anchor. These are made of strong steel but don't weigh much. They are perfect for trailerable boats where you watch every pound.

Rick's Small SailBoats LLC doesn't just sell you a boat; we set you up for success. We pick the gear that fits your specific sailing spot. Whether you are on a lake or the coast, we make sure your "parking brake" actually works.

Don't let the confusion of marine charts keep you on the dock. We are here to guide you through every knot and every breeze. From choosing the best anchor types for small boats to your first solo sail, we have your back.

Schedule an Appointment with Rick at - rick@rickssmallsailboats.com or connect at 954-579-1289

FAQs

1. Can I use a concrete block as an anchor? 

No, please don't do that. A concrete block is heavy in the air but loses weight in water. It has no "teeth" to grab the ground. It will just slide along the bottom while your boat drifts away into danger.

2. How much chain do I really need? 

For a small trailer sailboat, six to ten feet of chain is usually enough. The chain keeps the "shank" or the neck of the anchor down. This helps the sharp points stay buried in the sand instead of pulling out.

3. Is one anchor enough for my boat? 

It is always smart to have a "lunch hook" and a "storm anchor." A lunch hook is light and easy to move. A storm anchor is bigger and used if you have to stay out overnight or if the weather turns bad.

4. What is the best rope for my anchor? 

Three-strand twisted nylon is the gold standard. It is strong, it floats a little, and it stretches. That stretch is important because it acts like a shock absorber when waves hit your boat, protecting your deck hardware.

5. How do I know if my anchor is dragging? 

Pick two fixed points on the shore, abeam (90 degrees to the side of your boat) like a tree and a house. If those points start to move apart or change position, you are moving. It is time to pull up the gear and try setting it again.