Anchors - yet again

Danchc

Danchc

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Hi all

I have lost track of how many anchor threads there are to search through, so I thought I would ask a very specific anchor question.

Take the Delta vs Rocna anchors. The Delta has a flattened 'A' shaped spade, while the Rocna has a flattened 'V' shaped spade. According to some magazine reviews (which may not be very accurate) the Rocna has a better chance to embed and a greater holding capacity - but this does not mean it is actually better in real life.

So, which is better: 'V' shaped spade or 'A' shaped spade?

Note that the actual question no longer asks about specific anchor makes :)
 
FWIW my pref would be ultra then delta then rocna. Both A and V can hold a boat, and there isn't a universal "best" becuase sea bottom varies so much. You have to factor in lots of issues and compromises and I have had delta on last few boats and specced on my new boat. TBH they will all be fine, with the right length and weight of chain etc etc.
 
I've retrofitted Delta anchors to my last 2 boats and they just work for me. Never dragged, never had a problem getting them out. I don't know whether you know but there has been some issues with Rocna anchors when they moved production to China. Do a search on these forums and you'll find plenty of detail on this
 
Danchc said:
So, which is better: 'V' shaped spade or 'A' shaped spade?
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Large numbers of attempts have been made to find significant differences, and all have failed. Both work well. Both are much better than old generation anchors. The reason for such strong differences of opinion is because there is no detectable difference, so you are just left with opinions.

Choose the one which best fits your hawse . . .
 
Have always used ploughs (ie CQR similar) and so far they have never dragged. Usually we anchor in mud or sand. They seem to set easy and reset after tidal stream reverses or wind direction change.
 
hlb said:
My secondhand, bent plough, worked fine.

The biggest problem most folk have, is skimping on the chain. A big brick would probably work as well as an anchor.
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totally agree with you HLB, I have used Bruce anchors on my last 2 boats and we anchor quite a bit and have never dragged. always used 3x chain to depth + a bit depending on state of tide. Saw with some horror a while back someone attempting to anchor at East Head in a Bayliner, down the anchor would go and then full astern at around 8 knots. He did this about 6 times, each time he would eventually stop to avoid hitting another boat, up the anchor would come and he would reposition himself and once again repeat the process, I guess he thought one of his full astern excursions the anchor would bite and the boat would come to a grinding halt meaning his anchor was now set.... obviously that never actually occurred which meant that after about 40 minutes of rib tickling fun he motored off in the sunset shaking his head and probably wondering what he had done wrong! :rolleyes::D
 
Firefly625 said:
totally agree with you HLB, I have used Bruce anchors on my last 2 boats and we anchor quite a bit and have never dragged. always used 3x chain to depth + a bit depending on state of tide. Saw with some horror a while back someone attempting to anchor at East Head in a Bayliner, down the anchor would go and then full astern at around 8 knots. He did this about 6 times, each time he would eventually stop to avoid hitting another boat, up the anchor would come and he would reposition himself and once again repeat the process, I guess he thought one of his full astern excursions the anchor would bite and the boat would come to a grinding halt meaning his anchor was now set.... obviously that never actually occurred which meant that after about 40 minutes of rib tickling fun he motored off in the sunset shaking his head and probably wondering what he had done wrong! :rolleyes::D
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Sorry NO!

He will have anchored off into the sunset complaining about his anchor being no good.

(Then condemn it in some post on here! :D)

Mike
 
What about this one.

Up until recently we usually found a marina berth for the night but now in the med late afternoons turn into staying the night so the anchor question crops up.

We only anchor when the weather is really good, not a fan of the rock and rolling all night. Do you keep someone up all night on anchor watch even in good weather ? (we don't)

Whilst having a beer with one of the captains along the quay anchoring came up, his view was for an overnight stay just dump the whole lot of chain out, ie in a pile on top of the anchor, he didn't say it but I think he means undo the clutch on the windlass and let the lot out.

His view is that you would hold absolutely anything with this approach plus swing circle would be really small.

My usual method has been 4 or 5 x depth, small astern to let the anchor grab, if it doesn't move all day then all night shouldn't be a problem either.

So dump the lot in a pile on top of the anchor or lay 4-5 times out in a line ?
 
MRC said:
What about this one.


So dump the lot in a pile on top of the anchor or lay 4-5 times out in a line ?
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I learnt this one the hard way a long time ago. We were chartering in the Caribbean for the first time and anchored overnight in a deserted bay. First lesson learnt was that a boat attracts other boats even if the whole stretch of bay is equally suitable for anchoring. I did actually stretch out the chain and check the anchor but i know now that it was only partially dug in and needed a few more feet of reverse to be sure one way or the other.

Anyway another boat anchors behind us, but before going off to a restaurant I dump a whole load more chain, "to be safe" following the idiot principle that chain left in the locker is a waste. While getting happy fed and drunk a squall blew up and all the shutters in the restaurant had to be closed.

We paid up quickly and motored out to our boat which was a fair way out to find it was dragging with its stern being fended off from the bows of the boat which had anchored just behind us.

Much hassle and angst followed up anchoring then out in the dinghy in the dark to lay a second anchor to be secure for the night in the strongish winds.

Didn't work out until the next morning that we probably hadn't dragged at all, just stretched out our pile of chain until we were in contact with the other boat.

Since then I've always made sure that the chain is dropped slowly once the anchor has hit the bottom and that a decent amount of reverse is applied to drag the anchor the few feet needed to dig it in. That way when somebody drops their anchor by your stern there is an excellent chance that stronger conditions won't put you back on them.

I also often see the technique of peole putting their boats in hard reverse then slowly dropping chain while the boat charges backwards through the anchorage, often biting hard after a few attempts, and often not. In Croatia that seems to be the recommended techcnique, perhaps from somebody once overhearing, "to dig the anchor in you must put boat into strong reverse".
 
MRC said:
So dump the lot in a pile on top of the anchor or lay 4-5 times out in a line ?
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I'm no expert, but as I understand it, chain and anchor resting on the seabed will not stop you drifting. The seabed is supporting the weight of the anchor and chain.

Your boat is supported by chain in the water, or the friction of chain along the seabed, or the grip of the anchor. Anything in a pile does nothing.

If you don't believe me, tie a piece of string to a bag of sugar and coil surplus string on top of it. Then hold the other end and move it about with no difficulty. Only when the string goes taught against the bag will you see the resistance, the same resistance as the anchor does for your boat.

Not quite the same as chain is heavier than string, but until the weight of the chain off the sea bed plus the friction of the dragging chain equals the force of drift, your boat keeps moving (as RupertW found out). Or, of course, until the anchor grabs sufficiently.

It's physics.......
 
Hmm I would choose V- shaped anchor because it is known for its good quality, performance and reliability. Well if get the chance I would rather choose V shaped becoz it has a greater holding capacity. So choose the one that suits you best.
 
hlb said:
A big brick would probably work as well as an anchor.
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Well I suppose if it was a really big brick, the type some people refer to as a mooring block, then it'd work just as well :D

I get what you're saying about the chain doing lots of the work, and in light winds then for sure your brick (or just the chain) would do the job, but as the wind/tide gets up you need the anchor to stop the chain dragging horizontally along the sea bed. Anything that also drags would need to be unfeasibly large and heavy to do the same job as something small and light that digs itself in.

I've also had occasions when the anchor has momentarily had to do all the work, because the wind has been strong enough to lift all 60m of chain off the sea bed (anchored in a mistral off Le Lavandou). Very uncomfortable, but the boat stayed put.
 
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Nick_H said:
Well I suppose if it was a really big brick, the type some people refer to as a mooring block, then it'd work just as well :D

I get what you're saying about the chain doing lots of the work, and in light winds then for sure your brick (or just the chain) would do the job, but as the wind/tide gets up you need the anchor to stop the chain dragging horizontally along the sea bed. Anything that also drags would need to be unfeasibly large and heavy to do the same job as something small and light that digs itself in.

I've also had occasions when the anchor has momentarily had to do all the work, because the wind has been strong enough to lift all 60m of chain off the sea bed (anchored in a mistral off Le Lavandou). Very uncomfortable, but the boat stayed put.
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+1

Even a sailing boat engine in reverse at quarter revs can drag a heavy anchor the few feet needed to dig it in, and that's a tiny force compared to even a brief rain squall passing through. A similar weight of brick would just keep on dragging. The chain is great for getting a decent flat pull to the anchor but doesnt hold the boat in anything but light winds. Awth any small force it will just stretch itself out along the bottom until the anchor holds it taut. Now a quarter ton brick will do it far better of course.
 
Having just returned from a great trip which had some really mixed weather i have decided if we are going to anchor we have to be really sure of the weather of have someone on anchor watch.

On a windy day last week we anchored in the bay around the corner of Port Vauban, the wind was offshore, approx 30 knots. Strong enough to have that snatching effect on the anchor. We decided to head back to the comfort of the berth for lunch.

An hour later the wind picked up and swung round 180 degrees. There was A large sailing cat which was moored next to us, guessing it had 60M of chain out plus the cat was approx 30M. This means the swing radius was approx 180M. Being moored close enough to the shore meant it possibles became to close after being dragged and ended up on the rocks.

A really really sad sight and the sight of seeing someone looting her the following days made me feel horrible inside. This was / is someones boat. I was going to post pictures but decided against that too.

If anyone knows the owners I hope all ends well with it.


In fact not a good week for people being moored or berthed next to us, the night after we left San Remo the boat next to us caught fire and destroyed a maiora and Pershing 90.
 
Wow MRC that sounds dreadful. Was there any crew on board the cat at the time she dragged?
 
I'm guessing no crew on board. Port Vauban was madness for an hour or so with ribs and tenders flying in and out of the marina, i mean 30knotts rather than the 3k limit , I'm guessing collecting crews from the town and heading back out to boats at anchor outside the marina.

There were white horses in the marina.

Seeing it makes one feel quite sad about it.
 
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