Why Every Boat Should Carry An Anchor Weight And How You Can Buy One For Virtually Nothing.

 

If you are a member of the 'buy a bigger anchor' brigade, then you may be missing the point of what an anchor weight actually does.

If you're anchored in a full gale, in uncertain holding conditions, then a really big anchor and a lot of chain is definitely the way to go. And who would argue with that? 

But If you're a coastal sailor who enjoys a quiet night at anchor, perhaps in a crowded anchorage or on a shallow river, then a chum weight is definitely worth investing in. 

To anyone new to sailing, an anchor weight, sometimes known as a chum weight, anchor buddy or anchor angel, is simply a weight you slide down your anchor chain once you've safely anchored.

If you're an old hand, then you probably have an opinion on this controversial subject already. 

A quick search through the internet boating forums reveals some quite polarized views on the topic. 

Whilst writing this article, I have read quite a lot of comments on the subject, across many forums, and my overview is that they tend to fall into two broad categories. 

The 'do the math' type opinion, based on catenary calculations and equations that point out that a chums weight has a negligible contribution to an anchor's ultimate holding power once the anchor chain is at full stretch, versus the anecdotal, 'I actually use one in real life anchoring situations and it works', in which the benefits of an anchor weight, used across a variety of anchoring situations are enthusiastically extolled.

So, physics versus practical experience then.

There are quite a few noteworthy, utterly credible, very experienced sailors who understand the benefits of this simple anchoring strategy. You may use it only once or twice in a season, but you'll be glad you have it on board when you do need it.

Why Every Boat Should Carry An Anchor Weight And How You Can Buy One For Virtually Nothing.

Here's a quick run down of the pros and cons. 

Pros:

Reduces Boat Swing: 

Adding a weight to your chain will reduce the swinging circle of the boat.

This is particularly useful in crowded anchorages when the various underwater profiles of your neighbours boats means it can be difficult to predict if you will swing towards each other at the turn of the tide or in a wind shift.

Easy to Store:

For the average cruising boat, an 8 to 12 kg weight should be sufficient. This doesn't add anything to overall boat displacement, so it's a good 'find it when you need it' solution.

Dampens Snatching:

A weight on the chain dampens snatching. Who needs that all night? 

Of course you could argue that this is a snubber's job. I use both, but the anchor weight is primarily to relieve the snubber by changing the underwater dynamics of the chain, and how it behaves. 

Providing a better solution for a quiet night's sleep.

Prevents Entanglement:

A chum weight will beef up a chain and rope set up, and also weigh down the rope to stop it wrapping around keels, rudders or anything else, in slack conditions.

Alters Chain Angle:

Anchor weights can significantly lower the chain's angle of pull on your anchor.  Perfect for poor holding situations or when you're obliged to anchor on short scope. 

Reduces Shearing:

I own a twin keeled boat. A chum weight reduces the amount of shearing or 'ranging' at anchor. 

Shallow Waters: 

Useful in shallow anchorages when you have a lot of chain out, but no catenary effect. 

Catenary is the curve that anchor chain makes when it hangs between two points, helping it absorb pressure and hold the anchor securely. In a shallow anchorage, the chain will simply lie on the seabed. 

Where catenary is absent, an anchor weight can aid holding.

Little Harm, Big Psychological Boost: 

It does no harm to add the extra weight of a chum to your set up, but the psychological benefits are worth the effort!

Decreases chain movement:

And finally, in light conditions, an anchor weight can reduce the amount of chain movement across the sea bed as your boat is effectively pivoting around the chum weight, and not the anchor.

Surely this is a better outcome for the seabed? 

In an era where conservation is important and we have come to understand the value of seagrass,  this alone must justify using and owning one.

 Cons:

Ineffective Without Catenary:

There's no benefit in adding a weight to the chain once the catenary disappears. 

More Chain Is Better in Strong Winds

More chain will always be better than an anchor weight in severe conditions.

But…there won't always be times when you can't let out more chain.

Author, cruising sailor and Yachting Monthly contributor, Ken Endean states :

'A chum is the most useful precaution. It enhances holding, damps snatching and it's easy to recover if you have to move. Complicated underwater gear that may have to be unrigged in the middle of the night is thoroughly undesirable'

Sailing writer and broadcaster Tom Cunliffe notes in his video 'Tom Cunliffe and his ancient anchor weight'.

  "... in shallow water, however much chain cable you lay, sooner or later it comes up tight and you lie pulling to anchor [snatching].  In very deep water the weight of the chain helps and it doesn't happen so much. It's less than ideal".

"Another situation that's less than ideal is when you're anchored with lots of boats around you or in a very tight place and you can't lay as much scope as you want but you know you're probably okay and the holding grounds decent, but you end up on two to one or two and a half to one scope which really isn't enough".

"That situation was assisted by weighting my cable… and moving the catenary forward ".

Eric Hiscock writes in his cruising classic 'Cruising Under Sail' that he used a 28 llb weight on a four and a half ton boat for many years and suggested that larger vessels might use three separate weights for ease of handling. 

Mirelle writes on ybw.com forum,

'In the past 22 years of sailing my boat in the southern North Sea and the English Channel, I have used a "chum" four or five times, and been very glad of it each time. It is not an everyday measure, but it can be very handy… anchoring in a tearing hurry on shingle, in a narrow channel - rope round prop, dead header, too narrow to tack (moored boats each side), three knot tide...to wait until I could sort things out. On this occasion we were dragging until I used it, so I can specifically say - it works. I don't, of course, anchor in such spots from choice'.

My personal viewpoint is that while you may not need an anchor weight all the time, it's indispensable when you do.

You can buy various anchor weights online under trade names. Mine is a lot cheaper and was on sale at Aldi for under £10 a few years back. It's a 9kg plastic coated kettle bell! 

Easy to handle and carry around the boat and it has a flat bottom so stores well in a locker.

With a twin keel boat that's constantly hunting and ranging about the anchorage, the anchor weight is the equivalent of a short leash. I wouldn't be without it,