All About Anchors

[maxingout]

Originally Posted by Mike OReilly

More than anything, I watch for good technique. Good technique can make a marginal anchor work well. And conversely, there can be no saving a boater using poor technique, regardless of the anchor.

I think we focus too much on equipment, and not enough on technique.

In a place like the Bahamas with all the charter boats, there is limited technique and lots of optimism. I like to see those optimists with limited technique use the Manson and Rocnas when they anchor near me.

[thinwater]

Originally Posted by maxingout

In a place like the Bahamas with all the charter boats, there is limited technique and lots of optimism. I like to see those optimists with limited technique use the Manson and Rocnas when they anchor near me.

LOL.

[Mike OReilly]

Originally Posted by maxingout

In a place like the Bahamas with all the charter boats, there is limited technique and lots of optimism. I like to see those optimists with limited technique use the Manson and Rocnas when they anchor near me.

I don’t disagree. This is the benefit of these new-gen anchors; their margin of error (so to speak) is wider. They are simply better at setting, and function well in a wider variety of substrates, so they are easier to use.

In some ways, they can mask poor technique. But I’d certainly rather have a new-gen anchors over the older styles (as a bower).

[Razoo]

Originally Posted by maxingout

In a place like the Bahamas with all the charter boats, there is limited technique and lots of optimism. I like to see those optimists with limited technique use the Manson and Rocnas when they anchor near me.

That's a pretty good technique you use lol.

[Razoo]

Originally Posted by GRIT

I know this is an unhelpful reply, but I have to assume you're bored and want to poke the wasp's nest.

[a64pilot]

Unless you run a performance boat and really try to save weight, I see no downside to oversize a new gen anchor, I often anchor where I do because it’s poor holding and I get to be by myself, and or when things are tight, I can hold well at less than optimum scope.

From what I have seen, the charter boats are first to the morning balls, and they can have them.

[motion30]

Originally Posted by Mike OReilly

Well, this question has been discussed to death. There is no answer everyone agrees with. However, I will give you my answer.

Extensive evidence, both from controlled tests and anecdotal experience, indicates the newer spade-style (new-gen) anchors are the best overall performers. Anchors like Spade, Rocna, Manson, Mantus, and a few others.

Rode. Most cruisers (people who anchor in a wide range of areas and conditions) favour all-chain rode. Some boats cannot carry all-chain due to weight. And there are benefits to rope/chain as well. All-chain seems to be the most versatile rode.

As to anchor size, my view (which is not supported by everyone) is to get the largest spade-style anchor your crew and your boat can reasonably manage. By this I mean big, but not so big it is overly taxing on your crew or the boat (windlass, roller, storage system, etc.) such that it becomes overly difficult to deploy and retrieve.

Some here prefer a more specific answer. For that I would turn to the tables provided by the various anchor manufacturers.

Mike stated my feelings exactly I have been anchored continuously for the last 3 years

[Don C L]

Yeah the good technique of others is something I consider too, but MOST especially those who are anchored upwind of me. Downwind, I wish them luck, and may offer a word of advice. Upwind, a boat with poor technique (i.e. poor anchor and scope,) or just too dam close, I'll likely move. Mike's right about scope too. If you ever dive on your anchor you can see that with enough scope a rock can hold your boat well, for a while.

I am sure most of us have great ol' anchoring stories... I think they are probably compelling because we are always wondering just what is going on down there!

[thinwater]

I've done lots of anchor testing; load cells, the whole thing. What is most interesting, to me, is the scatter in the data. It's normal to see 30% scatter, and 50% scatter is not unusual, even with NG anchors. Why are some sets poor in what seems to be relatively consistent bottom? Does it really make that much sense to argue over 10 pounds, when the test variation is huge? The answer is yes, I suppose, because we NEED that safety margin.



Normally you can dive on the anchor and find the answer. Trash. A tree branch. A random soft spot. But not always; the problem was concealed, underground. Often as not, the anchor would have held your power set, just not a strong storm. Fortunately, most sets improve with time.


Curious.

[a64pilot]

Yes, but.
There is always a but isn’t there, except for trash usually if there is enough scope an anchor will dig itself in very quickly when it begins to drag, so drag through the soft spot etc and it sticks, likely happens pretty often, we just don’t know it, cause it hooks up pretty quick.

I’ve only drug excessively once, and during that long slow drag I let out a ridiculous amount of scope to no effect.
I was never really in any danger and was experimenting.
Way too muddy and nasty to dive on it to see what was going on, I with a little help from forum members later came up with a theory that my stupid oversized Rocna was laying on its back, in soft mud and the mud was so soft the roll bar couldn’t right it, so I was dragging an upside down anchor.

[Razoo]

Originally Posted by thinwater

Normally you can dive on the anchor and find the answer. Trash. A tree branch. A random soft spot. But not always; the problem was concealed, underground. Often as not, the anchor would have held your power set, just not a strong storm. Fortunately, most sets improve with time.

I always dive on my anchor before and after giving it a 1/3 reverse throttle. Sometimes 1/2 throttle depending on where I am and what it looks like down there.

[kas_1611]

Originally Posted by Mike OReilly

More than anything, I watch for good technique. Good technique can make a marginal anchor work well. And conversely, there can be no saving a boater using poor technique, regardless of the anchor.

I think we focus too much on equipment, and not enough on technique.

Mike has a good point about technique. Many a time I've seen a perfectly good anchor being thrown over the side with a mile of chain behind it while the boat in question is still going forward at several knots. Engine slammed in reverse to stop it then cut and the beers cracked open. Boat probably ahead of the anchor and certainly no setting force applied to it.

It doesn't matter how big, shiny or expensive your lump of metal is, how sharp the pointy end is, how wide the roll bar is if you just dump it on the seabed with chain piled on top of it. If you don't take the time to drop it carefully, laying back a good scope (3:1 minimum, 4:1 better for all chain, more if you can) then giving the boat some reverse to help the anchor dig in, giving it a bit more then a bit more then you only have yourself to blame when you drag.

Even if you do do all that and the anchor holds 1800rpm in reverse there is no guarantee, no matter how new generation or big the lump is, that you won't drag. We did in 40kt winds in Vilho Bay last September despite having given the Vulcan 2000rpm in reverse for 2 minutes but I think that was due to the chain having swung over or around the anchor when the wind shifted nearly 180º. Thankfully we were able to reset safely and it took a lot of jiggling to get the Vulcan to let go of the mud a couple of days later.

[Mike OReilly]

Originally Posted by Razoo

I always dive on my anchor before and after giving it a 1/3 reverse throttle. Sometimes 1/2 throttle depending on where I am and what it looks like down there.

I have only rarely dove on my anchor. Mainly b/c I mostly cruise in cold water where swimming is not an easy option. In warm shallow waters I’d certainly do the swim check, but absent this I’ve learned to use other technics to assess what is going on down below. Visual cues and measured transits are essential. How the chain behaves when setting and digging in says a lot. The feel of the chain or rope under strain communicates loads about what is going on down below.

Originally Posted by kas_1611

Mike has a good point about technique. ...It doesn't matter how big, shiny or expensive your lump of metal is, how sharp the pointy end is, how wide the roll bar is if you just dump it on the seabed with chain piled on top of it. ...

All well said Kas. . When a boat anchors upwind of us it is a great comfort to see them using good technique to set and dig in their anchor — whatever anchor they use. And conversely, someone who demonstrates poor technique is someone to move away from.

All this said, it’s a fact that most boats do manage to stay put most of the time. Even in cases where I've doubted their technique, most boats don’t drag away. It sometimes makes me second-guess my rather anal approach to setting and digging in.

But in the end, I like to sleep well, so I ain’t gonna change .

[GordMay]

Originally Posted by Mike OReilly

I have only rarely dove on my anchor. Mainly b/c I mostly cruise in cold water where swimming is not an easy option. In warm shallow waters I’d certainly do the swim check, but absent this I’ve learned to use other technics to assess what is going on down below. Visual cues and measured transits are essential. How the chain behaves when setting and digging in says a lot. The feel of the chain or rope under strain communicates loads about what is going on down below...

Indeed.
A vibrating or thrumming (rope) rode suggests that the anchor is dragging.
If you back down, and the boat jerks to a sudden stop, you may assume the anchor has caught.
I always let the anchor "soak" for a moment, then backed down full throttle. Even so, reverse thrust doesn't simulate storm wind conditions.

[Razoo]

My primary is a 70 Rocna with 300' chain {a little over kill, but once set I'm not going anywhere}


Secondary is a 55 Rocna with 300' chain.


I have no stern anchor and personally I've never come across a situation where I would need one....yet.