Minimum anchors size, what’s the point?

[Mike OReilly]

I expect my bower to manage the vast majority of anchoring situations. My rule of thumb is that it should manage up to the edge of hurricane (~60 knots). And indeed, mine has done that a number of times. 40+ knots is pretty normal for where I cruise right now.

My storm anchor is NOT easy to deploy. It is significantly over-sized, and will take time to set and dig in. It is to be used when a predicted major storm (hurricane) is headed my way and I have the time to plan and deploy a more extensive anchor layout.

I guess you could always deploy what I'm calling a storm anchor. But that would exceed my guideline of being reasonably easy to manage by boat and crew.

[valhalla360]

When you start talking extreme, cost does come into play once you get above a reasonable sized anchor..

Lets say for a 30' boat a 30lb anchor of a particular brand is the recommended minimum:
- Move up to a 40lb version, might add a hundred or two to the anchor price and likely the handling won't be significantly different (same bow roller, winch, etc...)
- Move up to a 100lb version will likely be drastically more expensive (possibly 2-3 times the cost)...plus you will likely need to upgrade the winch at substantial cost...The bed where the winch is attached and the bow roller may need to be upgraded at substantial cost...don't forget the electrical system feeding it...then if the winch fails, there is no option to manually retrieve, you have to rig up something to a winch in what could be bad conditions.

It becomes a game of diminishing returns once the anchor is big enough.

Another issue is if the anchor is so large that it's a hassle to deploy, if you don't get a good set, there is a much better chance that someone lives with a marginal set. It's fun to get on the high horse and say you should/would never do that but reality humans do silly things when they are tired.

[malbert73]

I think your primary should be robustly oversized to the point where you can handle it. Multiple anchors are great in theory but with most storms and frontal passages there are windshifts and greater chance of fouling. Undersizing so that windlass isn’t needed is not a great approach i think. Keep the undersized anchor and rode stored, and if the windlass fails drop the rode and mark it with a buoy.
But I think a fortress, way oversized, is a great storm anchor to keep stored. Unparalleled in straight line pull.
So I have mantus 55# as primary, fortress FX37 as storm, on 18000# displacement 40 footer as data points.

[Mike OReilly]

Originally Posted by valhalla360

... Move up to a 100lb version will likely be drastically more expensive (possibly 2-3 times the cost)...plus you will likely need to upgrade the winch at substantial cost...The bed where the winch is attached and the bow roller may need to be upgraded at substantial cost...don't forget the electrical system feeding it...then if the winch fails, there is no option to manually retrieve, you have to rig up something to a winch in what could be bad conditions.

See, this is where you’ve tipped over into being unreasonable. My suggestion is that you should get the largest NG anchor your boat and crew can reasonably manage.

(Not saying you don’t…) But I assume that most cruisers are reasonably intelligent and can be expected to make reasonable decisions based on their own judgment. Rebuilding your windlass/roller to accommodate an anchor that is five times larger than the manufacture’s recommendation is most likely unreasonable.

Originally Posted by valhalla360

It becomes a game of diminishing returns once the anchor is big enough.

And what is “big enough”? The largest NG one that can be reasonably managed by boat and crew. See … it’s simple .

Originally Posted by valhalla360

Another issue is if the anchor is so large that it's a hassle to deploy, if you don't get a good set, there is a much better chance that someone lives with a marginal set. It's fun to get on the high horse and say you should/would never do that but reality humans do silly things when they are tired.

Yes … this is another way of saying what I’m saying. It is certainly possible to go too big. If your boat and crew cannot reasonably manage the bower anchor, then it is likely too big. I would rather sit on an undersized anchor that is properly set and dug-in, than an oversized one that is just sitting on the bottom.

Originally Posted by malbert73

I think your primary should be robustly oversized to the point where you can handle it. Multiple anchors are great in theory but with most storms and frontal passages there are windshifts and greater chance of fouling. Undersizing so that windlass isn’t needed is not a great approach i think. Keep the undersized anchor and rode stored, and if the windlass fails drop the rode and mark it with a buoy.
But I think a fortress, way oversized, is a great storm anchor to keep stored. Unparalleled in straight line pull.
So I have mantus 55# as primary, fortress FX37 as storm, on 18000# displacement 40 footer as data points.

[daletournier]

Having multiple anchors for varying bottoms, really? Its quite a hassle to change my anchor.

How many cruisers , that cruise full time ever change from their primary to something else?

In all my cruising I've never felt the need for anything but my primary anchor. I understand maybe a big fortress dismantled and tucked away for that freak huge storm that you can see coming in advance (that you probably will never see).

The reality is, choose the right anchor, size it right, have enough chain, good snubber and dig it in.

Something I do think is important is being able to drop the anchor and chain if for some reason you need to. This means making sure the chain can run free. A problem I have is my chain consistently twists on my current boat, this is something that concerns me, it's never happened on previous boats or at least not to this extent.

[jmh2002]

Originally Posted by Mike OReilly

...I assume that most cruisers are reasonably intelligent and can be expected to make reasonable decisions based on their own judgment...

This is where it can easily go wrong...

[Mike OReilly]

Originally Posted by daletournier

Having multiple anchors for varying bottoms, really? Its quite a hassle to change my anchor.

How many cruisers , that cruise full time ever change from their primary to something else?...

I used to routinely do this before moving to a NG (Rocna) Dale. I carried a Danforth and CQR on the bow and would switch between them depending on the bottom. The key for me was to make both easily deployable, which I did with a custom-made holder/roller (actually, a buddy designed it for me).

One of the significant benefits or improvements with the NG anchors is that they pretty much cover the same range of bottoms as my dual anchor combo. I still think a Danforth-style is the best anchor in specific conditions, but I almost never deploy it now.

[valhalla360]

Originally Posted by Mike OReilly

See, this is where you’ve tipped over into being unreasonable. My suggestion is that you should get the largest NG anchor your boat and crew can reasonably manage.

Not always true. I can manage a 30lb anchor...but I would argue that's generally going to be overkill for the dingy. Likewise, if you put in a really big winch, you can reasonably mange a 100lb anchor but that will generally be overkill for a 30' boat.

(Not saying you don’t…) But I assume that most cruisers are reasonably intelligent and can be expected to make reasonable decisions based on their own judgment. Rebuilding your windlass/roller to accommodate an anchor that is five times larger than the manufacture’s recommendation is most likely unreasonable.

Except if you look at some of the responses to this thread, there are people suggesting much larger anchors compared to what some people are using with good reliability. In one, they suggested a rule that resulted in a 450lb anchor when the owner an owner has been very satisfied with a 140lb anchor (admittedly a larger boat than I'm used to dealing with)...which brings up another issue. I'm reasonably famiar with 30-40' boats but if I jumped up to a 60' boat, I would want an outside source to confirm what is reasonable as even though I have a fair bit of experience, I don't have experience with boats that large. Just for the fun of it I looked up prices.. a Rocna at 154lb is $2400 to jump up to 440lb is $7600.

And what is “big enough”? The largest NG one that can be reasonably managed by boat and crew. See … it’s simple .

Wrong, it the one that provides sufficient holding power for conditions. Do you spec a mast cross section that's 3 times the diameter because the crane that sets it can handle that much weight...once it's up it's just as easy to manage?

Yes … this is another way of saying what I’m saying. It is certainly possible to go too big. If your boat and crew cannot reasonably manage the bower anchor, then it is likely too big. I would rather sit on an undersized anchor that is properly set and dug-in, than an oversized one that is just sitting on the bottom.

I will agree with the last part but there very much a reasonable range for anchors and when you get outside that range, it makes little sense.

[Mike OReilly]

We're just going around in circles Val. The point is as a cruiser you are never going to know with 100% certainty if you have sufficient holding for the conditions. All you can control is what you deploy. So deploy the largest, most effective anchor and rode you and your boat can reasonably manage. I don't know why this is such a challenging suggestion for some.

You can present any number of unreasonable scenarios. Doesn't change reality. But if you're more comfortable going with the minimum size recommended by the anchor makers or tests, then go for it. That likely works most of the time.

[valhalla360]

Originally Posted by Mike OReilly

We're just going around in circles Val. The point is as a cruiser you are never going to know with 100% certainty if you have sufficient holding for the conditions. All you can control is what you deploy. So deploy the largest, most effective anchor and rode you and your boat can reasonably manage. I don't know why this is such a challenging suggestion for some.

You can present any number of unreasonable scenarios. Doesn't change reality. But if you're more comfortable going with the minimum size recommended by the anchor makers or tests, then go for it. That likely works most of the time.

The reason we are going in circles is you are giving a "how long is a piece of sting" answer but the tables provided have to provide real numbers.

Try not to side track the discussion by putting words in my mouth...I never suggested you should use the minimum size.

[Mike OReilly]

Originally Posted by valhalla360

The reason we are going in circles is you are giving a "how long is a piece of sting" answer but the tables provided have to provide real numbers.



Try not to side track the discussion by putting words in my mouth...I never suggested you should use the minimum size.

Wrong. It is you who is trying to provide a definite answer to an indefinite question, or to put it more colloquially: how long is a piece of string?

This is what all these tables are doing; trying to answer your piece of string question. I am suggesting cruisers turn the question on its head and look at the problem from the other end; from the end cruisers can assess and control.

[daletournier]

Originally Posted by Mike OReilly

We're just going around in circles Val. The point is as a cruiser you are never going to know with 100% certainty if you have sufficient holding for the conditions. All you can control is what you deploy. So deploy the largest, most effective anchor and rode you and your boat can reasonably manage. I don't know why this is such a challenging suggestion for some.

You can present any number of unreasonable scenarios. Doesn't change reality. But if you're more comfortable going with the minimum size recommended by the anchor makers or tests, then go for it. That likely works most of the time.

I just don't see a downside to your "deploy the biggest anchor......" comment. It just makes good sense.

[Mike OReilly]

Originally Posted by daletournier

I just don't see a downside to your "deploy the biggest anchor......" comment. It just makes good sense.

Thanks. Me too Dale.

P.S. Yes, I am bored right now. I'm hanging from my anchor right now, waiting out yet another Newfoundland 30+ blow. I'm comfortable swinging from my somewhat oversized bower, chain and hefty snubbers.

[thinwater]

Originally Posted by Mike OReilly

We're just going around in circles Val. The point is as a cruiser you are never going to know with 100% certainty if you have sufficient holding for the conditions. All you can control is what you deploy. So deploy the largest, most effective anchor and rode you and your boat can reasonably manage. I don't know why this is such a challenging suggestion for some.

You can present any number of unreasonable scenarios. Doesn't change reality. But if you're more comfortable going with the minimum size recommended by the anchor makers or tests, then go for it. That likely works most of the time.

You are going in circles for two reasons.


1. You can estimate holding capacity. Not true except in the pedantic sense. If you power set you can be rather certain up to the limits of the test, which you can easily calculate (compare engine thrust to wind load). Beyond that, you can feel what the anchor did and you can dive.
2. "Reasonably can mange" is not an answer, not at all. This is like "how long is a string." Come up with a number you can stand behind. Stick your neck out. I stuck mine out with "3% ABYC storm load for NG."

[Mike OReilly]

Thin, I'm not going to repeat myself (yet again). I seem unable to communicate to you and Val what seems to me (and many others here) to be a simple concept. You seem stuck on looking at the problem in one way, and I don't know how to say it clearer; I'm looking at it from the other.

I think my way is an answerable, practical question (at least for people who are able to be reasonable). The standard way treats anchoring as a theoretical problem.