Tips for Anchoring a Boat

Anchoring your boat is pretty easy if done the right way but can also be difficult if you are not using the right technique or the right anchor.  In this article, we will discuss how to choose the right anchor for your boat and proper anchoring technique.

First of all, know that it is advised to have an anchor and rode on your boat even if spending time on the hook isn’t one of your chosen ways to pass the time out on the water.  I have talked to many boaters who claim that they do not need an anchor because all of their time spent on their boat is either at a dock or underway.  My question to them is always the same:  What if you are underway and you have engine problems or, in the case of a sailboat, you rip a sail?  Are you comfortable drifting around at the whim of the wind and current?  If your boat does not have an anchor, get one.

Ground Tackle

An anchoring system (or ground tackle) for your boat is comprised of three components:

1.       The anchor – The most obvious of the components.  This is what fastens your boat to the bottom.  While some people mistakenly assume that the weight of the anchor is what holds the boat in place, it is actually the anchor design that determines its holding capacity.  One of the best anchors that I have had on any of my boats was actually the lightest.  Most modern anchors are designed to dig into the bottom resulting in holding the vessel in place.  While anchor weight may not hinder the anchoring process, it is not necessary to make it effective. 

The anchor's ability to dig into the bottom is what makes it effective.

2.       Chain – This is where weight is important.  Most recreational boaters use nylon rope for their anchor rode.  This is primarily because it is lighter and less expensive.  Some larger vessels with windlasses may use all chain.  If you are using nylon rode, it is still recommended that you have at least 7 to 10 feet of chain between the anchor and the nylon line.  This helps keep the shank of the anchor flat on the bottom allowing the anchor to do its job more effectively.  The size of the chain depends on the size of your anchor and rode.  You can use an anchor swivel to connect the chain to the anchor on one end and braid the nylon rope to the chain on the other end.  You can find anchor line that is pre-braided to a length of chain to make this process easier. 

3.       Rode – This is the total length of rope/chain that you have for anchoring the boat.  The length should be based on the typical depth of water that you anchor in and the size or thickness is based on the size boat and anchor.  It is recommended that you mark or tag the rode at periodic lengths of 10 or 20 feet so you will be able to measure how much rode is being let out.

Complete setup of anchor, chain and rode.

Anchor Types

There are a few decisions that you will have to make when buying an anchor, mainly the type of anchor and the size.  The following are common anchor types:

Danforth (sometimes called a fluke) – Works well in clay sand or mud bottoms. 

Danforth Anchor

Plow or Delta – Works well in sand, hard mud, grass and pebbles.

Plow or Delta Anchor

Bruce – Works well in sand and mud.

Bruce Anchor

Mushroom – Good for silt and mud.  Has excellent holding power but only after it had had ample time to sink into bottom.  Often used for markers and mooring balls. 

Mushroom Anchor

Each anchor type comes in different sizes to adapt to different size boats.  Be sure to purchase the right size for the boat that you have.  An anchor that is too small may not hold your boat in windy or rough conditions.  In fact, I sometimes purchase an anchor a size larger than required provided that my boat’s anchor storage will accommodate it. 

Types of Rode

When selecting the rode for your anchoring system, the two most common types are three strand nylon and chain.  Nylon is an excellent option because of its strength to weight ratio and its ability to stretch.  Most recreational boats use nylon as opposed to chain because of its lower weight and cost.  Some larger boats may use chain because of its superior strength and ability to make practically any type of anchor more effective.  On my personal boat, I also chose to use a full chain rode because chain tends to feed through a windlass with fewer problems. 

When purchasing rode, you need to know two things:

1.       The typical depth of water in which you will use the anchor - This is where scope comes in.  As mentioned previously, modern anchors are designed to dig into the bottom to be effective and this means that the shank of the anchor must be parallel to the bottom for it to work properly. In other words, the anchor must be able to lie flat on the bottom.  To achieve this, you must let out an amount of rode that is multiple times what the depth is.  Scope is defined as the ratio of rode to depth that you let out in order to set your anchor.  Technically, the more you let out, the more effective your anchor can be at holding the boat in place.  To allow your anchor to be effective, you should plan for a scope of at least 5 to 1.  If you are anchoring for the night or the weather is a bit windy, then a 7 to 1 scope is recommended.  Storm conditions would require an even higher ratio.

For example, if I am dropping my anchor and the water depth is 20 feet and I am going to use a 7 to 1 scope, I would need 140 feet of rode. 

2.       The size of your boat will determine what size rode you need.  The table below show typical rode sizes (in thickness) for different size boats. 

Boat Size	3 Strand Nylon Size	Chain Size
21 to 30 feet	3/8”	3/16”
25 to 35 feet	7/16”	¼”
29 to 40 feet	½”	¼”
33 to 45 feet	9/16”	5/16”
37 to 50 feet	5/8”	5/16”
41 to 60 feet	¾”	3/8”
49 to 70 feet	7/8”	½”
57 to 80 feet	1”	5/8”

Heavier boats and boats with more windage should be equipped with anchor rode in the heavier of the two ranges.  For example, if you have a 35 foot boat but it is very heavy or is a fly bridge, 9/16 inch 3 strand nylon is recommended rather than ½ inch.

How to Anchor Your Boat

The process of anchoring your boat is easy if you follow the right procedure.  If you use this process every time you anchor your boat, you will find it quick, easy and reliable.

1.        Know the depth of the water – This is usually done be way of a depth finder.  If you do not have a depth finder, you can find the depth on most charts but that method is not as reliable.

2.       Determine your scope – based on conditions and how long you plan to stay at anchor, decide what your scope is going to be and use that to determine how much anchor line you will be putting out.  If the area that you are anchoring in is crowded, make note of other boats in the area and be sure that you allow enough space for your boat to swing around the anchor if the wind or current changes. 

3.       Make sure the boat has come to a complete stop and then lower the anchor until approximately 2/3 of the desired rode is out.  Note that it is not recommended that you throw the anchor.  This can cause fouling which can result in a failed attempt.  Simply lower the anchor into the water.  Once 2/3 of the rode is out, back the boat up until you feel the anchor “set” (grab the bottom).  At this point, you put the boat in neutral and let the rest of the rode out. 

4.       When you are ready to retrieve the anchor, move the boat forward as you pull in the rode.  When the bow of the boat is directly above the anchor (rode is vertical in the water), stop the forward movement of the boat while continuing to pull in the rode.  Eventually, the rode will pull upward on the anchor shank, thus releasing the anchor from the bottom.  Continue the retrieval process until the anchor is completely up.

Proper Anchor Setup

When at anchor, it is a good idea to check periodically to ensure that your anchor is holding the boat firmly in place.  Here are a few ways to do this:

1.        Make note of the boats location compared to a stationary landmark (if near land) and make note a few minutes later.  If there is a significant change, you may be dragging anchor.

2.       Put your hand on the anchor rode and check for vibration.  If the anchor is dragging across the bottom, the rode will be taught and you should be able to feel the vibration.

3.       If you have a GPS/Chart Plotter aboard, check to see if it has an anchor watch feature.  If so, use it.  It can detect your boats movements and sound an alarm when the anchor appears to be dragging.

4.       There are anchor watch apps such as Drag Queen and My Anchor Watch that you can get for your smartphone that can detect when your boat is dragging anchor.  Note that some of these apps can cause your battery to drain faster. 

Don’t forget, spending a bit of money now on a good anchoring system for your boat and learning how to anchor can save you tons of headaches in the future.  You may even find that you enjoy spending time just relaxing on your boat in a quiet cove somewhere.  Look at it this way.  The more time you spend at anchor, the less fuel you will use.  Eventually, you will recoup the cost of the anchor and line.

Don't forget to comment in the comment section below and thank you for reading.

Happy Boating

Captain Frank

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