Anchoring with 4:1 Scope?

[Mike OReilly]

Originally Posted by Dockhead

Well, but there is no sense in just more more more for its own sake. To get a rational answer to this you need to consider other factors -- quality of your anchor, size of your anchor, bottom condition, depth of the water, weather.

Except, that's not what I said, and I think you know that. In fact, based on your description of your own approach, you do exactly as I suggested. And I don't know where this "Fetishizing scope" comment comes from. No one I know has ever done this.

I agree, to be rational one needs to consider a wide variety of factors. You've listed a few. I'm sure we could extend your list quite a bit. And that's the point. To be truly rational is to admit that you can't know all the factors when anchoring. So, to be rational, one should build in a margin of error, or as I put it, be conservative.

Clearly that's what you do, even with your massive gear. Otherwise, and in your own words, you should only rarely put out more than 3:1, but you do "in bad weather more." That's not rational, unless your bad weather is a hurricane.

So all good .

[Mike OReilly]

Originally Posted by Chotu

...I can also see why everyone else uses their engine to pull on the anchor to try to set it. I literally throw mine overboard and dump out 10:1, or at worst case, 8:1. Nature does the rest. Never dragged once in my life and I’ve lived at anchor more nights than on land in my life.

I agree with your choice of scope, but I hope you're being a bit facetious with this description Chotu. Just throwing the anchor and dumping out 10:1 is a terribly risky approach.

As to allowing nature to set and dig in the anchor, that can clearly work a lot of the time, but it also leaves a lot to chance. This seems at odds with your closing line:

Originally Posted by Chotu

If you can take away the uncertainty in boating, why wouldn’t you do that?

[sailorboy1]

Why do fourum make anchoring seem sooooooooooooooooooooooo hard?

I wish everyone would add their boat name to their user name signature etc. so we know how worried to be if you show up.

[MicHughV]

I don't get these anchoring threads....the answer is simple....there is no common denominator !!!!....each boat is different, every boat will have different anchors, each anchorage you arrive at will determine what you should do. Most boaters have more than one anchor, more than one rode, etc...use what you think is best for the situation....following a 4:1 or 7:1 rule is nuts !!

[Palarran]

Originally Posted by sailorboy1

Why do fourum make anchoring seem sooooooooooooooooooooooo hard?

I wish everyone would add their boat name to their user name signature etc. so we know how worried to be if you show up.

Oddly enough, I agree with you. Choice of scope tells me a lot about a sailors preparation and skill level, and not even limited to anchoring.

[MicHughV]

I've lost track of the number of different anchors available to the yachtie.....different rode setups, different boats, different bottom holding, different experience, etc, etc, etc..when you pull up to an anchorage you will have no idea who is using what, at what scope, what depth....none...nada...zilch...
it's one huge mish-mash.....

[SV__Grace]

We love our Sarca Excel!

When I first installed my new Excel the first thing I did was test it at shorter scope than I usually use for our 20 ton ketch.

So in a familiar anchorage in 30 knot winds, we spent one day at 4:1 and the anchor didn't move.

The next day, similar conditions, shortened to 3:1 and the anchor didn't move. However it most likely was pretty well dug in from the previous day so that's not a fair test of 3:1.

But, as someone who used to get anxious at anything less then 7:1, this helped me become comfortable with shorter scope, on this anchor anyway.

Been using it for a year or so of full time cruising and living on the hook, and it always sets fast, has never dragged, and is always in the same spot when we raise it (no matter how many swings). I still like lots of scope for fresh conditions, but no longer stress if in a crowded anchorage and need to shorten scope.

[PirateGuy]

Anchor holding is mostly a function of what substrate the anchor is set it. On one extreme, a flat, hard rock bottom will prevent any anchor from digging in and holding. At the other extreme, very recent sediments (mud) such as deposited at the mouth of large rivers have such low shear strengths, that most normally sized boat anchors will not hold either.
I have found the CHIRP sonar I recently added to my sensor suite to give me a pretty good idea of bottom conditions, especially if rocky or with coral heads. A strong bottom return signal (which is quite distinct from the fuzzy return in soft mud) is also useful.
4:1 or 10:1 doesn’t matter much in a blow if you are anchored on muck.
As for just throwing your anchor out and dropping a 10:1 scope without bothering to set your anchor by pulling on the rode - you don’t seem to have ever tried to anchor in thick sea grass where the anchor has a hard time even getting to the sediments that will actually hold your boat in place

[SV__Grace]

Originally Posted by hpeer

Quick story.

We go into Dehies, in Guadeloupe. It is a sort of narrow bay, open to the Caribbean, moderate sloping sides and the central bit is quite deep with some soft mud. Because of the mountains the wind frequently shifts and can swing you right around and be real gusty. And it is real popular, its best to go in early in the day to find anchorage room. I have had a guy hit is while trying to anchor.

So we go in, grumble, grumble; the best I can do is a bit deep and in the mud. We drop our 125# Mantus and set it. We go clear in and are grabbing lunch, Im watching the boat. 180° wind shift (or more) and I get a bit nervous so I head out solo to check.

By the time I get to the boat we are a whisker from kissing another boat. I motor up and retrieve the anchor. The anchor is fouled in the chain. It cleared itself as it came out of the water but I could clearly see it fouled.

What I THINK happened is that in the weird 180° shift the slack chain drug back over the shank and fouled it. This occurred because the boat drifted directly back over the anchor.

The other possibility is we fouled the anchor when we set it, but I had backed down hard and she held solid. About 4:1 scope. Now its possible it set into some rock and dropped out when she swung but thats kind of far fetched.

Would more scope have helped? I do not think so, thats just more chain to wrap around the anchor. Less chain? Maybe, but there are other considerations.

Dehais is a funny place and can be a bit challenging in many ways. It seems we never go there with out obtaining a new story. I thought this one might be interesting concerning scope issues even if it is an odd situation.

125# Mantus is a huge anchor that will weather a hurricane when well set, but I wonder what happens when a boat swings before the anchor is well set.

I'm imagining the chain could catch under the wide ears (where the roll bar is bolted) or under (instead of over) the shank, both of which I think could dislodge an anchor.

I love Panope's videos and often wished I could view my own anchor when I wanted. Great challenge for an entrepreneurial techie. I did invest in an underwater camera drone but haven't had the time to master controlling it- not as easy as the marketing videos show!

[Stmurray62]

ASA and USCG Aux, to my knowledge, recommend 7:1, it’s not rediculous.

[moseriw]

Oh my this damn x:y never ending story. Throw out whatever you can or have and a cool beer.

[Don C L]

Originally Posted by moseriw

Oh my this damn x:y never ending story. Throw out whatever you can or have and a cool beer.

Now let's see, what's the name of your boat? You don't mind if I anchor upwind of you do you?

[contrail]

Originally Posted by SV Siren

Not to throw a wrench into the conversation, but here goes anyways

My boat when I purchased her, came with a rather large kellet. Does anyone use these much anymore, and should I keep it. I have rather oversize ground tackle now on all chain..

Yes, and yes. Made a big difference in a hurricane I rode out.

[SaltyMetals]

The question the OP posed was a difference in scope. I thought Steve's/Panope recent video of the testing of a small Spade "S60" (10Kg/22lb) was interesting. It buried quickly at 3:1 but would drag slightly. At 5:1 there was only slight drag and at 7:1 it was "solid as a rock" (Steve's words).

I happen to use a spade on a 13m (43ft) Jeanneau but it is a larger one (S100 20Kg/44lb) and usually set at 5:1. If I do not have more swinging space and am worried about the weather I let the snubber out to its max (about 10m/30ft), secure it and then let out a lot more chain so that the chain makes a large heavy loop which will then lower the angle the chain makes with the shank of the anchor and at the same time will dampen any swinging of the boat.

Then i relax and have a cool beer and good night's sleep.
Andrew

[Don C L]

Originally Posted by SV Siren

Not to throw a wrench into the conversation, but here goes anyways

My boat when I purchased her, came with a rather large kellet. Does anyone use these much anymore, and should I keep it. I have rather oversize ground tackle now on all chain..

The kellet has received some discussion in the past. I think the consensus is that it may be useful for shock absorption but does not add to the holding power of the anchor. Only scope does that.

On another item, when folks say "my anchor has always worked great and never let me down" I don't count that as validation of an anchor's abilities. Every anchor holds until it doesn't. One stormy night I had what I thought was enough scope on what I thought was the best anchor, a CQR. This was many years ago. It dragged. But then again so did the fishing boat behind me and the little wooden sloop next to me. Now those folks did not even wake up. The boat dragged about 50 yards and then took hold again. I always wondered if they woke up and noticed they had dragged. My point is that if you have 3:1 or 4:1 on any anchor on a stormy night, and it holds, I suggest to count yourself as lucky rather than a good judge of anchors.