Do you re-anchor when wind/tide changes direction?

[Mataji]

My anchor dragged last month.

I had anchored in 4 metres, soft mud, very sheltered (Puilladhobrain). I expected less than 5 metres at HW so I let out 25m of chain. Wind was F2 to 3. Stayed overnight and in the morning the wind had gone round nearly 180 degrees to northerly. I hadn't moved all night and wind was still light. Decided to go for a walk with a couple from another boat. Fortunately for me the other couple cut their walk short and returned to their boat. The wind had suddenly piped up to about F5 and as they were getting into their dinghy they saw my boat suddenly begin to move rapidly backwards. They gave chase (they had an outboard), boarded my boat and let out another 10 meters of chain and the boat came to rest. I got back half an hour later and found I was in 1.9 meters with the tide falling. (For those that know the place, I was just south of the wrecked fishing boat but on the opposite - eastern - side).

Question is - should I have relayed the anchor following the wind change? When we first anchor we ensure the anchor is well in. But when we swing we often rely on the anchor resetting itself. Some anchors are known to reset better than others (mine's a Delta) but not many people just drop it and hope it will set itself!

 

[RupertW]

Never did whilst sailing in a tidal area and haven't dragged due to tide change. I have sometimes anchored from bow and stern to remove any doubt.

I never quite had the courage to the the bow and stern anchor both coming from the bow, partly because I didn't think would be obvious to other anchorers that I would not swing the same way they did, and partly becauase I wasn't confident about it remaining untwisted.

Now I sail in non-tidal waters but with very variable winds I still don't reset it but am wary of being too long away from the boat if the wind gets up a lot. So far the anchor has mostly stayed the same way round once dug in, with the chain going round but in stronger winds it has clearly turned over or around but within the sand not a full reset.

 

[Sgeir]

I would not expect to re-anchor if it's been properly set in the first place. I know that boats have occasionally dragged in Puilladobhrain but given the glutinous nature of its mud, the main problem there is usually getting the anchor back out again.

I hope you don't mind me making a couple of observations without criticism being intended. First of all, the area south of the mooring is normally only used by shoal draught boats. It's very shallow, and the area facing the wrecked fishing boat dries out completely. If you were south the wreck, there must have been very little water under you. Just guessing, but is it not possible that perhaps you didn't drag, but that the 25m of chain just swung around?

 

[jimbaerselman]

These posts on the live-aboard forum debate the subject:

http://www.ybw.com/forums/showthread.php?435688-Rotating-on-anchor-in-tide

 

[Mataji]

No, I was originally anchored well north of the mooring boy, almost level with the blue rope. She dragged a long way. I was surprised that the anchor had not reset before she got so far. When I recovered the anchor there was some weed on it, not that much and it could have been picked up any time during the drag.

 

[Sgeir]

No, I was originally anchored well north of the mooring boy, almost level with the blue rope.

Thanks for the clarification - that was a pretty spectacular drag then!

I had trouble once setting the Kobra 2 anchor in either Loch Aline or Puilladobhrain. On recovering the anchor I found that the fluke had gone clean through the top of a very old can of Tennent's lager, the kind that were adorned with photos of ladies with nice dresses. Much have been lurking in the mud for at least 30 years.

 

[NormanS]

Thanks for the clarification - that was a pretty spectacular drag then!

I had trouble once setting the Kobra 2 anchor in either Loch Aline or Puilladobhrain. On recovering the anchor I found that the fluke had gone clean through the top of a very old can of Tennent's lager, the kind that were adorned with photos of ladies with nice dresses. Much have been lurking in the mud for at least 30 years.

I had that once many many years ago in Granton harbour, with a sailing dinghy. Please, cruisers, don't dump your old tin cans (or any other rubbish) in harbours and anchorages.

To the OP.
No, I never re-lay my anchor just because the wind has gone round, but you might just have been unlucky with a bit of weed etc.

As my boat is at present languishing at anchor in the Outer Hebrides for a month, I protect against the need for the anchor resetting, by using two anchors in a "Bahamian Moor". But I wouldn't want to do that every time I anchored.
Is your anchor and chain up to the job? What weight of anchor and chain? What size of boat?
If my boat was to drag in a F5, I would be very disappointed (and surprised).

 

[Mataji]

I was surprised. The boat is 28ft. The anchor a 10 kg Delta with 8mm chain.

 

[NormanS]

I was surprised. The boat is 28ft. The anchor a 10 kg Delta with 8mm chain.

That seems reasonable. Do you by any chance have a short bit of line on the tripping hole, which could have got caught on the chain, and caused the anchor to trip? Maybe it was an army of big crabs that walked away with it. In other words, I dunno. The mud in Puilladobhrain gets well ploughed by boat's anchors, but is still usually good holding.

 

[JumbleDuck]

I spent a very windy couple of days in Loch Moidart last week, with the boat swinging all round the anchor with every tide change. Didn't shift an inch, as far as I could tell, though since the wind was pretty consistently easterly in direction I expect the pull at the ebb, when I set it, was a lot less than the pull at the flood. I have had an anchor (knock-off 15lb CQR on smaller boat) drag in a herringbone pattern as it constantly reset with varying wind at right angles to constant tide in Ardinamir.

I'd be tad concerned about an anchor which needed 35m of chain to get a grip in shallow water and a bottom as good as Puilladobhran. Sounds as if it's rather seriously undersized.

 

[Mataji]

The anchor is a 10 kg Delta which is oversized for the boat (28ft), and there was nothing tied to it. I have had this anchor for 2 years, previously had a CQR, and have never dragged before. I was amazed at the distance it dragged and by the speed the boat went at (which was witnessed by my friends). One possibility is it caught some weed when it turned which prevented it from turning over and it slid on its back. We shall never know.

 

[vyv_cox]

Currently anchored in Arkangelos, north of Leros. In this notoriously shifty anchorage you would be reanchoring every few minutes. During our meal last night we rotated a full 360 degrees one way, followed by the same in the reverse direction. This is not in balmy breezes but in big gusts from every direction. During one massive gust we heeled so much that the wine bottle on the table fell over, fortunately it had been re-corked, and we held onto our glasses. A first for us.

 

[KellysEye]

>I had anchored in 4 metres, soft mud

That's the problem rather than any anchor issue. We always tried to avoid it and move to where we could find hard mud. 25% power on the engine in reverse will find if the anchor drags in soft mud, sometimes there is hard mud underneath and it will set, or soft sand . The other one we had problems with was what looked like a sand bottom was sand over rock, again we moved.

 

[NormanS]

>I had anchored in 4 metres, soft mud

That's the problem rather than any anchor issue. We always tried to avoid it and move to where we could find hard mud. 25% power on the engine in reverse will find if the anchor drags in soft mud, sometimes there is hard mud underneath and it will set, or soft sand . The other one we had problems with was what looked like a sand bottom was sand over rock, again we moved.

The mud in Puilladobhrain normally gives excellent anchoring.

 

[pmagowan]

Quite a lot of people seem to drag there. I think the best holding is just behind the island on the left as you go in. We sat out a gale there but not many of the dozen or so other boats remained through the night. Most scarpered to Oban. How did you set your anchor in the first place and how many revs did you use. Essentially if you don't test it to a greater pull than it might get by weather conditions you can't be sure it will stick. There is quite a bit of weed there, especially that long stringy stuff and it can clog the anchor if it is not well set.

 

[jimbaerselman]

Quite a lot of people seem to drag there. I think the best holding is just behind the island on the left as you go in. We sat out a gale there but not many of the dozen or so other boats remained through the night. Most scarpered to Oban. How did you set your anchor in the first place and how many revs did you use. Essentially if you don't test it to a greater pull than it might get by weather conditions you can't be sure it will stick. There is quite a bit of weed there, especially that long stringy stuff and it can clog the anchor if it is not well set.

And once an anchor is clogged, changing direction of pull becomes very risky, unlikely to re-set. Poly containers, fish netting, weed, stones, logs - I've hitched on to all of those over the years.

So, yes, I re-anchor if there's a change, or routinely do a running moor if it's not going to foul nearby single anchor folk.

My last visit to Puilladobhrain there was no possibility of a moor. The place was crowded, everyone lying to the NW in a light wind. Then the wind shifted to SW, reached about F4 by midnight. Absolute chaos. Thank heavens for those light midsummer nights . . .

Here's a "before" picture, looking SW:

 

[NormanS]

If it's as busy as that, I don't go in, there are plenty of other good anchorages close by.

 

[Deleted member 36384]

Quite a lot of people seem to drag there. I think the best holding is just behind the island on the left as you go in. We sat out a gale there but not many of the dozen or so other boats remained through the night. Most scarpered to Oban. How did you set your anchor in the first place and how many revs did you use. Essentially if you don't test it to a greater pull than it might get by weather conditions you can't be sure it will stick. There is quite a bit of weed there, especially that long stringy stuff and it can clog the anchor if it is not well set.

+1 exactly my experience.

To the east, nearer the shore I can pull my old CQR backwards easily at full chat, towards the entrance, exactly where you indicate I could dig in the CQR. I do not trust Puilladobhrain as I have see boats drag, especially in the fishing boat area. I am not sure how soft the bottom is closer in but I can imagine that the stream has dumped a lot of fine slate like silt which has never compacted and can shear quite easily. It is also a well anchored area as folks don't have to row far for the walk over the hill. The good thing about the island / entrance area is that everyone goes straight for the pool middle, so this area is nearly always vacant when the place is quite full.

 

[Pleiades]

Hmmm, 10 kg is too light for serious anchoring of a 28 footer in my umble opinion, unless its a 28 foot skiff. Doesn't matter what brand of anchor. I have always held on the old rule, one lb of anchor for every foot of boat length as a minimum - and I have never had to re-anchor in 45 years of almost all weather anchoring. Having said that, of course you don't know what is on the sea bed and even a well heavy anchor can drag if it hooks something slippery on the floor.
Get used to re-anchoring unless you are prepared to carry better ground tackle - some of the manufacturers' tables are for fantasy island anchoring.

 

[aquaplane]

Hmmm, 10 kg is too light for serious anchoring of a 28 footer in my umble opinion, unless its a 28 foot skiff. Doesn't matter what brand of anchor. I have always held on the old rule, one lb of anchor for every foot of boat length as a minimum - and I have never had to re-anchor in 45 years of almost all weather anchoring. Having said that, of course you don't know what is on the sea bed and even a well heavy anchor can drag if it hooks something slippery on the floor.
Get used to re-anchoring unless you are prepared to carry better ground tackle - some of the manufacturers' tables are for fantasy island anchoring.

No change of tide in Pullers, only change in wind which is less frequent and forecast.