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Anchoring

jendave1 6:54pm, 6 September 2010
We've noticed that many people don't like to anchor, or are worried about it somehow. Jenny & I have only been sailing since May but it has always been our idea to use the anchor. Partly this is because we like to get into quiet spots and watch the sunset from our boat, and partly because I'm too tight to pay for mooring!
I thought it might be an idea to post the topic to boost confidence & share experience; we think it's a far better thing to stay in a spot you like for free rather than end up in a gaggle of bigger yachts & gin palaces.
Our A24 has a plough type (CQR copy) anchor about 8kg that sits in the anchor well, with about 5m of chain & 20m of rope (8mm 3 strand terylene). Because anchoring was going to be our thing, I got another (12kg CQR copy) with 10m heavy chain to which I spliced 20m of 15mm rope.
The first thing is to try it out to build up your confidence. The first time we anchored I didn't get any sleep, kept opening the hatch and looking out every hour! Round here we have lots of sandy beds, which work best for us. First thing we look at the tides and work out the lowest & highest level to decide where we can rest without hitting the bottom. You have to allow for the swing which can be quite a bit when the wind or tide changes, make sure it won't sweep you into shallower water.
We then select our spot using the depth gauge; I'm not happy with ours so usually check with a stone on a rope! To be fair if you're in clear water you can often look over the side and get an idea of the depth. We drop the anchor and let the boat ride back onto the warp; we try to get 5x the maximum depth of chain & warp. Raising the anchor by hand means the shallower the better! We never motor back against the anchor, I think this is the wrong thing to do to set an anchor as it doesn't replicate the actual forces of the boat moving and can set at the wrong angle or pull out when it would have been OK. We find it best to let the boat settle and in an hour or so the anchor is buried on its own.
I keep an eye out for the first hour or 2 for any dragging. It can be difficult to judge with the boat swinging, but the GPS helps to check if you've swung to the north or south etc. We tend to drop anchor, check for an hour then I take the dog ashore to do his business which lets me get a view of the boat from a distance and check it isn't moving.
Our single light anchor has worked every time on its own except once, when we were on a muddy bed. We found that if the anchor does drag, its a slow process so you can catch it before there's a problem if you're keeeping your eyes open (or use the GPS alarm, we've never bothered). In that instance we just motored forward and re-set the anchor, then I set out the second anchor from the tender at about a 45 to 90 degree angle from the first. Our second anchor set-up would hold the QE2, its way over the top.
I think a chain & rope combination is best, the rope has a bit of stretch which keeps shock loads off the anchor, while the weight of the chain holds the anchor flat and stops chafing of rope along the bottom. As the boat pulls away the chain weight means it lifts slowly, again absorbing shock and keeping the boat comfortable.
If there is a strong wind forecast I lay out the second anchor, as a sort of insurance rather than a necessity. With our little A24 dragging 2 anchors & all that chain it will move very slowly, even if they aren't on the bottom!
If you listen while lying in your bunk you can hear any change well, and you should hear the vibration if the anchor is dragging along the bottom, or if the wind's getting up you can check you haven't moved. If you think you've moved a bit, the best cure is to let out more warp (assuming there's room) which gives more shock absorption & holding power.
It's not so much the strength of the rope but the stretch that helps. You don't need chain all the way onto the boat, in fact that would give a poorer holding, be more noisy and jerk the boat more.
Give it a try and save yourself a few quid!
Mike A1 8 years ago
An excellent idea for a topic. I’m a big fan of anchoring. The main problem I find is that in many places where you might want to go ashore there are so many moorings that it isn’t possible to find anywhere to drop the anchor. However, there are still plenty of secluded spots where you can spend a very peaceful night – although some of my early nights were anything but peaceful – see below.

My main anchor is a 20lb CQR copy (this just fits into the anchor locker) on 10m of 8mm chain and 20m of 12mm 8-plait rope. I also have an “angel” which is a couple of meters of chain that is bundled up and lowered down the anchor rode on a length of rope, so it is about 2 meters from the bow. This is a well-known way of increasing the holding power of an anchor but the reason I use it is to prevent the anchor rope from getting wrapped around the keels. I’ll explain what used to happen as it might help someone else avoid the same problem.

What I found before I used the angel was that if the wind was against the tide, the boat would get blown forward and sheer around from side to side. Eventually, the rope would get caught under one of the bilge keels (Amare has a triple keel). Then, the boat would be held almost exactly side-on to the current. Even with a knot of current the tension in the rope was incredible and it would be completely impossible to pull in the anchor, and almost inevitably I would start to drag. With a rope under the boat it was too risky to run the motor. To get free, I had to drop the remaining anchor rope on over the side (with the bitter end tied on!) and the extra slack would allow the rope to drop under the keel.

Perhaps other people have suggestions for how to avoid this but I think it is less likely to happen on a fin keel. Anyway, since using the angel I have had no problems. I’m sure it would be just as effective to have all chain, but I don’t really want the extra weight forward. Ideally, I’d like to have a lump of lead since that would be even more effective.

As far as my technique for anchoring is concerned there are a couple of differences from what Dave wrote (purely person preferences of course – everyone has their own way of doing it and there isn’t a single right way).

Firstly, I normally dig the anchor in with the engine. This usually means the anchor comes up with a huge lump of mud on it and getting rid of this without spreading it over the boat is a real pain. In fact, this is probably the most difficult part of anchoring since I rarely have the luxury of a crew. Secondly, I always set the anchor drag alarm on the GPS. Depending on the conditions I might set this to go off when the tide turns, just to check that everything is alright when the pull on the anchor has reversed.

I’d be interested to hear other people’s ideas and experiences.

Mike
jendave1 8 years ago
I never thought about the rope catching on a bilge keel. Ours is a fin, and we've not encountered that problem. We always seem to lie away from the anchor under the greatest influence of wind or tide, although the warp isn't always taut.
I thought an angel was an excellent idea, I've been keeping an eye out for one of those old cast iron scale weights to use (people always seem to have them as door stops!).
You are wise to use the GPS alarm, I'm a light sleeper and the slightest thing wakes me but one night it won't...
I wonder if the mud on the anchor is more to do with the sea-bed than motoring it in. When we've been in mud the anchor comes up covered in the stuff. We look for sandy bottoms wherever possible (Frankie Howard?) as they grip well and the anchor comes up clean. Also we're spoiled around here with sandy beaches.
Mike A1 8 years ago
Round here (the East coast) sand is rare and in any case if you can see what the bottom is made of, you're aground.
busy home [deleted] 8 years ago
Avoid iron ,,, anything,,, it rusts and makes a mess in the bilge
Ive a lead angel on a loop made with a polythene tube .
My anchor is a new Fortress ,, no well on Goskar I carry it in the lazerette and clip it on ,,One problem .... as it s very light .I cant tell when it touches bottom ,,, seems to hold well enough ... The Fal is tight shale and soft mud up river ,, Not easy ,,
jendave1 8 years ago
Feeling very spoiled now with sandy beds and clear water! I'll forget the cast iron weight then and go for lead.
pjbharrison 8 years ago
What weight would be recommended for a lead angel?
pjbharrison Posted 8 years ago. Edited by pjbharrison (member) 8 years ago
Here's an interesting article on anchor angels/kellets

www.petersmith.net.nz/boat-anchors/kellets.php

Worth a read
Also
www.petersmith.net.nz/boat-anchors/catenary.php
Red Marlin 8 years ago
I changed last year from CQR to a Spade. My wife got nervous when the CQR pulled out a couple of times and had to be reset. I always motored it in as when I snorkeled to see what was going on the CQR was always laying on its side and needed digging in. The Spade drops point down and digs in immediately every time and gives us a great deal of peace of mind. Also have 60 metres of chain and an anchor winch (got an angel but do not need to use it now). OK for our 9 metre the spade cost 600 euros which is a hell of a lot but when we spend months at a time at anchor we feel it was worth every penny.
Amrum 9171Y 8 years ago
Good topic - very interesting! I inherited a Chum anchor weight traveller from my father when I cleared out his house earlier this year. He used to swear by it on his A 9m, and I found it hidden in the garage. I haven't had the opportunity to try it yet, but I'll post some pictures of the leaflet I also found which describes it.
rothwell_neil 8 years ago
The Solway is sand and mud and I have the following. A 7kg CQR connected to 40M of 6mm chain and a further 10M of warp just in case. I use this in case of quick anchoring as it is connected to the chain and is in the locker. I find that occasionally it doesn't set too well and may require a couple of tries to bed in. I was also slightly concerned that whilst it never dragged it only seemed to bed in on one fluke as there only ever seemed to be mud on one fluke. For that reason I have a fall back that I always go with when I want a good nights sleep or it is blowing a bit. I carry a 16 lb Danforth anchor on the pullpit and use this whenever I want to be sure. This always seems to set first time, and has never moved. I think the Danforth is ideal for the west coast up through Scotland as in the sand and mud these anchors work well.

As to why do I use 40M of chain, because I have it and don't see why not to use it as it sits well on the chain. I hear comments about riding better to warp but I still think that a lump of anchor with lots of chain helps you sleep much better anyway. Other advantage of chain is that you have less out so move around a smaller circle.

For me the ideal would be an Aluminium Fortress as works like a Danforth but lighter for the same holding power. I would still get one too big as better to be sure and have a good nights sleep.
jendave1 8 years ago
Great to see other peoples thoughts & experiences.
I've just had a look at the link from PJB and read through. It seems to me that the graphs & supporting mathematics are a bit flawed, because they are considering an instantaneous state where the force is 'x', whereas in fact the anchor is a dynamic system and the forces are constantly varying. So the conclusion that the angel is having no effect is flawed because it will have a greater effect when the loads are less, and in fact contributes to the dynamics of the system as a whole.
Similarly I have a problem with losing the catenary curve and the rode being 'bar tight'. With the dynamic system the curve will be increasing and decreasing continuously under the sort of conditions found in a swelling sea, even with a constant wind force. Of course if the force is too great the system will fail (either anchor drags or rode snaps).
I also have a distant memory of suspension bridge design, where the cable is the limiting factor of achievable span. The problem being that the weight of the cable strung between 2 points can exceed the breaking strain of the cable itself - ie it is impossible to pull the cable 'tight' between 2 points because it will snap before it loses the catenary curve.
I don't have the time or the inclination (or the funding!) to go into the system in detail, just making the point that just because computer simulations have been run it doesn't necessarily translate into the real world situation. (Don't get me started on CO2 & global warming!).
blueachilles 8 years ago
Blue has 10m of chain and a good length of warp. We tend to use a Danforth, although there is a CQR on board. We anchor for lunch from time to time but I have never been brave enough to stay overnight.

We are just back from a Greek flotilla where we used anchors most nights, either bow or stern to a quay, or free swinging. We had an electric windlass on the bow with all chain, so we were very happy to lay out as much as we wanted.

What concerns me about having mostly warp on Blue is that there seems to be no weight in it. We had a night of F6-7 at anchor in Greece, and held because we had most if not all of the chain out.

I don't feel as confident on a small amount of chain and the rest rope; I understand about the chain keeping the pull on the anchor horizontal, but 10m of chain + 5x depth of warp never seems enough?

Judging by comments above, it seems I should be more confident! (?)
Red Marlin 8 years ago
Just had an e mail from a friend. He had a problem on Androsand like a lot of us he has bought a modern design anchor, a Rocna in his case. He ran aground coming in to port where the ferries had churned up an unmarked shallow area. He used his Rocna to try to kedge himself off without success. But the Rocna digs itself in so well he was not able to recover it manually and needed assistance from the Port Police at great cost. Lesson learnt if I need to kedge I will use my Bruce not my Spade. Blue has found what is commonly learnt in Greece. Which is why we have our spade/electric winch/60 metres of chain. - Tony
rothwell_neil Posted 8 years ago. Edited by rothwell_neil (member) 8 years ago
Ron

Thinking of getting a Fortress for Xmas as my Danforth is a tad old and rusty. Did you go for the FX7 or upscale to the FX11? FX7 claims to be adequate for up to 30 knots but may go up for those really bad nights. How is your experience?
busy home [deleted] 8 years ago
I bought the small fx7 but would go up one size,,,
I ve not used it in anger at all,, just easy no wind situations
Its very micky mouse in size and weight, but the reports are brill,,
Only difficult bit is knowing when its hit bottom ..
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