Anchoring overnight (peacefully)

To suggest that unless you have, at least, 100m of chain then you should not anchor in anything but light winds is ludicrous and proven invalid by the numbers of people who anchor safely and have done for years using less chain and or mixed rodes. As mentioned cordage weighs bugger all, contributes nothing to catenary and was used by thousands, and possibly still is. Moveover if you think deploying 100m of chain in 20m of water without an anchor will hold you in 30 knots of wind or more please let me know where you are and I'll go anchor as far away from you as possible.

Jonathan
 
Neeves said:
To suggest that unless you have, at least, 100m of chain then you should not anchor in anything but light winds is ludicrous and proven invalid by the numbers of people who anchor safely and have done for years using less chain and or mixed rodes. As mentioned cordage weighs bugger all, contributes nothing to catenary and was used by thousands, and possibly still is. Moveover if you think deploying 100m of chain in 20m of water without an anchor will hold you in 30 knots of wind or more please let me know where you are and I'll go anchor as far away from you as possible.

Jonathan
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Perhaps, Jonathan, one should consider that poster, in the words of a British liberal Chancellor and a Tory premier as "one inebriated on his own verbosity".
No-one should take him too seriously - I'm sure he's referring to the ultimate in poor bottoms - thin sand over rock.
Incidentally I can get 75m of chain and 100m of warp into the anchor locker of my 31' lightweight monohull. The most I've ever used was 75m mixed chain/warp in 28m of water off la Coruna. Generally in 10-20m water I put 40m of chain and between 5-10m of textile rode. Drags represent >1% of anchorings, both times due to foul bottoms.
I'd go so far as to say that it's ill-advised, on my boat and on most modern underwater shapes, to have no textile in the length of rode.
 
Neeves said:
For Oz, In Sydney a King Tide is a bit over 2m, Bass Strait, 3m, West Coast Tas, 0.3m but up north certainly 10m (not sure of max)

The market for G70 should be huge.

Does an off the shelf Benny, Jenny, Bav, etc have a locker that will take that length of rode?

Jonathan
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We enjoyed our sailing up the Queensland coast. Flat seas and abundance of safe Anchorage spots behind reef or up rivers. Shame about the Saltys.......

NT was another matter..... 8 to 14m tides, currents and then Darwin! Friendly locals but not a good place to have a yacht ⛵
 
Charles,

Thanks - I have often wondered how much chain (sorry maybe I should say rode) fits into an anchor locker of a smaller (with no disrespect) yacht. But I think your yacht is not of the latest, it has some miles under its hull and might have been more generously built. Are the lockers of current vintage Hanses, Bennys, Jennys and Bavs as generous?

I fully agree that everyone should carry enough cordage to act as a full rode, though I'd prefer a few metres of chain, as well, to drag on the seabed to minimise abrasion of the cordage. Equally one should use a good few metres of cordage as a snubber (as its elasticity offers cushioning upto whatever wind speeds you might want if you have sized your snubbers correctly)

Temptress - its harsh world up there, NT, Oz (and currently hot and steamy( - one of the advantages of the huge tides is a yacht can dry out and Darwin even has facilities to conduct same.

Jonathan
 
Neeves said:
Charles,

Thanks - I have often wondered how much chain (sorry maybe I should say rode) fits into an anchor locker of a smaller (with no disrespect) yacht. But I think your yacht is not of the latest, it has some miles under its hull and might have been more generously built. Are the lockers of current vintage Hanses, Bennys, Jennys and Bavs as generous?

I fully agree that everyone should carry enough cordage to act as a full rode, though I'd prefer a few metres of chain, as well, to drag on the seabed to minimise abrasion of the cordage. Equally one should use a good few metres of cordage as a snubber (as its elasticity offers cushioning upto whatever wind speeds you might want if you have sized your snubbers correctly)

Temptress - its harsh world up there, NT, Oz (and currently hot and steamy( - one of the advantages of the huge tides is a yacht can dry out and Darwin even has facilities to conduct same.

Jonathan
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Jonathan - Kelly's theory of relativity (boats position to bottom) relies on there being no anchor. Before we debunk this famous theory we should all try it.
 
> Moveover if you think deploying 100m of chain in 20m of water without an anchor will hold you in 30 knots of wind or more please let me know where you are and I'll go anchor as far away from you as possible.

I didn't say that what I said was that I view the anchor as the backup to the weight of the chain's catenary. I'm the only one who has ever posted depth to chain requirements here, when we were long distance I spent weeks testing the the length of chain required to stop dragging in different depths. The starting point was what length of chain allowed our boat to drag in a range 10 knots to 35 knots. When it did drag I let out more chain until the anchor reset and the figures are based on that. If the chain goes straight you will drag.
 
KellysEye said:
> Moveover if you think deploying 100m of chain in 20m of water without an anchor will hold you in 30 knots of wind or more please let me know where you are and I'll go anchor as far away from you as possible.

I didn't say that what I said was that I view the anchor as the backup to the weight of the chain's catenary. I'm the only one who has ever posted depth to chain requirements here, when we were long distance I spent weeks testing the the length of chain required to stop dragging in different depths. The starting point was what length of chain allowed our boat to drag in a range 10 knots to 35 knots. When it did drag I let out more chain until the anchor reset and the figures are based on that. If the chain goes straight you will drag.
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Pulling the chain straight does not lead to dragging except without anchor. A F6 gust will easily pull 40m of 8mm chain straight but does not drag in reasonable holding.
 
KellysEye said:
> Moveover if you think deploying 100m of chain in 20m of water without an anchor will hold you in 30 knots of wind or more please let me know where you are and I'll go anchor as far away from you as possible.

I didn't say that what I said was that I view the anchor as the backup to the weight of the chain's catenary. I'm the only one who has ever posted depth to chain requirements here, when we were long distance I spent weeks testing the the length of chain required to stop dragging in different depths. The starting point was what length of chain allowed our boat to drag in a range 10 knots to 35 knots. When it did drag I let out more chain until the anchor reset and the figures are based on that. If the chain goes straight you will drag.
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I didnt really want to get involved with this as these threads usually end in tears but I have to say I have rarely read such utter nonsense on this forum. In very light winds your bizarre theory might work as the loads on the boat from windage and waves are negligible. When the wind is at 40 knots the anchor chain will be a straight line. I know this because i have snorkled on my ground tackle in these conditions in the Caribbean. The anchor was not lifted off the bottom as the design of our spade anchor and many more like it buries the fluke and the shaft at the same time. It is to do with the geometry of the anchor. The more the wind gusted, the more the anchor dug in and the straighter the 40m of 10mm chain. All this with 19 tons of yacht hanging off the end. Your catenary does absolutely nothing in this situation. It is a fallacy if you think otherwise.
In addition to the above, we have been anchored in mud in Spanish Water in Curacao. Since our chain was going rusty we turned it around so the rusty bit was generally inside the locker we have 200 ft of chain and rarely deploy all of it. A mis-calculation when we rotated the chain with our chain markers ment we only had 25m of chain out. We thought we had deployed 40m. We were anchored for two weeks like that with wind up to 35kts. We didnt move an inch. Anchors are everything. Chain, rode or bed sheets tied together only need to be strong enough and long enough to give reasonable scope and keep you connected to your anchor. Catenaray is a complete joke in breezy conditions
 
"... but I have to say I have rarely read such utter nonsense on this forum."

+1

The anchor does the holding, and catenary counts for almost nothing. If holding is the issue, get a modern anchor that will hold.
 
MM5AHO said:
"... but I have to say I have rarely read such utter nonsense on this forum."

+1

The anchor does the holding, and catenary counts for almost nothing. If holding is the issue, get a modern anchor that will hold.
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I wonder whether people mix up catenary and scope and don't realise that scope isn't some magical thing but simply a way of getting a sufficiently shallow angle from the anchor to the boat - and that most anchors don't benefit much once that angle gets below 20-30 degrees because they are designed that way.

I wonder what some posters think the advantagea are of, say 16:1 compared to 8:1? Apart from absorbing snatch loads if the rode is elastic?
 
Furthermore if you have a good anchor and it is well buried, both the fluke and shank, then some or sometimes a long length of the chain is buried. The angle at the seabed is then, almost, totally irrelevant as its the angle at the shackle that is critical - and the shackle angle will actually be quite high and independent of the seabed angle. The shackle angle is high because when it buries along with chain these components resist burial and develop a reverse catenary.

Of course if you have an old fashioned or inefficient modern anchor or the seabed is very hard (and the latter would be most unusual) then the shackle will be on the seabed and the angle developed by the catenary is important - but beyond 7:1, or 8:1 the angle does not vary by much (or not enough to justify carrying all that chain).

The thinner your chain the less it resists burying. The ideal would by Kryptonite piano wire - if you cannot source this then HT chain is one thing to consider.

Jonathan
 
RupertW said:
I wonder whether people mix up catenary and scope and don't realise that scope isn't some magical thing but simply a way of getting a sufficiently shallow angle from the anchor to the boat - and that most anchors don't benefit much once that angle gets below 20-30 degrees because they are designed that way.

I wonder what some posters think the advantagea are of, say 16:1 compared to 8:1? Apart from absorbing snatch loads if the rode is elastic?
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The inexact business of anchoring produces all sorts of theories, but until now I have never seen anyone advocating a scope of 16:1. There's a first time for everything, I suppose. :rolleyes:
 
I understand the OP's feelings in this. We only started to relax overnight at anchor when we got wise to choosing anchorages that are close to bomb proof. Sure we trusted our gear but what if conditions changed? So we're conservative, we choose anchorages that are either safe in any direction of blow, like some of the hidy holes in Chichester Harbour, Poole Harbour or Abrahams Bosom by Butley Creek in Suffolk. If one of these isn't available in the passage plan then we plan for a marina or reliable mooring. It means we miss out on many beautiful anchorages that would be fine in 80% of conditions but not in 98%. But still this year we had just 6 marina nights in our five week cruise. Pick your spots, you know your gear works but you need to trust the gear and the location.
 
NormanS said:
The inexact business of anchoring produces all sorts of theories, but until now I have never seen anyone advocating a scope of 16:1. There's a first time for everything, I suppose. :rolleyes:
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Wow - who is advocating 16:1 - there's little point above 5:1 and almost none above 8.1
 
I always find these thread more filled with wind than information. The reason, of course, is that each person posts only a fraction of the whole story. If each person fully described their experience, there would probably be very little conflict. Well, maybe some.;)

* In shallow water (<3M) chain counts for very little. Whether the anchor drags depends on its holding at that scope (ALL anchors loose capacity with reduce ACTUAL scope measured at the bottom, generally about 30-70% by 4:1, but it depends on the design and the soil.)
* In progressively deeper water, the chain start to keep some curve even in strong winds. By 40-50 feet you may lift the rode off the bottom, but if you have respectable scope (>4:1), not that much with all chain.
* Heavier chain only matters in the middle depths; in the shallows it doesn't do enough, and over 40' light chain works too.

So at the end of the day, all of the posters are relating true experiences. I don't know much about anchoring in deep water (never over 15'--it's shallow around here), and I'll bet most posters don't know anything about shallow water (I consider 6-7' normal, and I go as thin as 3-4').

My main though is that anchor selection and rode selection are two separate discussions; the rode should be able to absorb shock and keep the bottom scope >7:1 at all times (measure at the bottom), and the anchor should be able to hold the tension. There are multiple ways of achieving each goal. Adding rode to a crappy anchor or expecting NG to deal with severe uplift and yawing are both mistakes. Solve the problems separately so that each can do its job properly. No single one-size-fits-all, unless you really like to hobby horse.
 
RupertW said:
Wow - who is advocating 16:1 - there's little point above 5:1 and almost none above 8.1
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If using an all-chain rode then I would have expected there was an advantage in higher ratios just due to the weight of the chain, is that not true ?

Boo2
 
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