New gen anchor "jerking" when set?

[Delancey]

I am well into my first real season with a new gen anchor, in this case a Mantus which others have described as very quick or aggressive in it's set. Sometimes within an anchor length if I recall other's observations correctly. Before that was mostly CQR or else Danforth/Fortress.

I have mainly been anchoring in mud and/or sand in ten to fifteen feet of water with fifty feet of chain and ten to twenty feet of three strand so functionally an all chain rode with a snubber.

Whether under sail or under power I rarely consider myself to be making much way when I set. At most two knots depending, usually less. I almost always experience what I would consider a jerk. This anchor seems to claw into the bottom so quickly there is no other way I can describe it. When I back down afterwards I rarely feel like the anchor is moving if at all from the initial jerk.

[Stu Jackson]

Originally Posted by travellerw

Hhmm I think you may be misunderstanding what they mean by "jerk"...

We do the exact same procedure (as you) on our boat and its unmistakable when the anchor sets.

It's easier to type jerk than unmistakable.

It's only a comparative term - i.e., compared to earlier anchors that dragged until they slowly "bit."

[Cthoops]

Thanks for the responses, everyone. Taking all of them into account, it makes perfect sense now why we don't feel it when the anchor bites.

Originally Posted by redhead

I had the same question on a previous boat. I was a new sailor and didn't get any nuances. I went to the bow and as we drifted back I was told to put my foot lightly on the rode. When the anchor set I immediately felt it through the rode and I didn't have to learn it again. When motoring back I look hard at the bow and you can see a slight dipping of the bow when it sets.

I offer this because you said you had anchored with it less than 20 times and I know these tips helped me. Good luck.

These are great suggestions, and we'll definitely put them into use this season.

Originally Posted by Stu Jackson

It's easier to type jerk than unmistakable.

It's only a comparative term - i.e., compared to earlier anchors that dragged until they slowly "bit."

Mr. cthoops teasingly calls me "literal woman" as I can tend to be a bit too literal with things. "Jerk" vs. "unmistakable" is a perfect example of that!

Originally Posted by Shrew

@ Cthoops

Are you using an all chain rode, or are using using a mix of chain and nylon line?

The combination of the gradual process and nylon rode picks up any hit. I would bet those folks talking bout feeling the jerk are either using all chain rode and/or backing down very quickly.

We use a mix of chain and nylon, so that's also likely a big part of it.


Thanks again!

[JPA Cate]

We back down in idle reverse. Jim sometimes has his foot lightly on the chain as it pays out. The Manson Supreme, in our usage, does not jerk, but unmistakable is a good word for what happens. As we're idling back,I feel the anchor snubbing, going slowly, it does not jerk, and nor is there a jerk when I back down hard on it. Jim usually snubs it twice or three times, before he gives me the signal to increase the revs and verify our position by ranges. My best guess as to what's happening is that backing down may bury it further--or not--but as long as the ranges stay put, I'm a happy camper.

Ann

[desodave]

In our part of the world, when you get a real "jerk" setting an anchor, it means you've probably buried it in a rock crevice, or possibly nailed a bit of old logging debris with it.

[Jim Cate]

My take is that when there is a jerk involved, he likely doesn't set the anchor at all!

Jim

[StuM]

Originally Posted by Jim Cate

My take is that when there is a jerk involved, he likely doesn't set the anchor at all!

Jim

[zeehag]

it is a wonderful ka lunk feeling wherein the boat suddenly turns 180 degrees. and that is my bruce setting in mud/sand/rocky bottoms of west coast.

[markpierce]

Definitely feel a jerk when the anchor sets. I don't set the snubber on an all-chain rode until the anchor is set.

[TheThunderbird]

I drop along Boatman practice

I look for an elastic reaction from my all chain rode (motoring mildly backwards), no jerk desireable. (Suspicious!)

I use snubber only under sustained winds, the anchor already set.

Jim&Cate, why paying snubber 2-3 times? I dont get it right.. :-)

[rwidman]

Originally Posted by Cthoops

When I read an anchoring thread, it's almost inevitable that one or more people will comment that they feel a "jerk" when their new gen anchor sets - you can't miss it, I have to hold on, etc.

We are not yet full-time cruisers and are relatively new to anchoring (less than a dozen times so far), but we use a Rocna on our Bristol 29.9 (and our previous Bristol 24) and not once have we felt a "jerk." We are as close to stopped as we can get when we drop the anchor and we let the wind drift us back while slowly paying out the rode before eventually backing down with the engine. The anchor has always been deeply buried.

I'm definitely not trying to start yet another anchoring argument. I'm simply curious as to why we don't feel a "jerk" with our Rocna when so many other people have commented on one. Does it have to do with the fact that we're always anchoring in mud or sand? The size or weight of the boat? The size of the anchor? The way people anchor?

You didn't say if you have an all chain rode or combination chain and line. It makes a difference. Line stretches and absorbs and shock or jerk. Chain does not.

[Suijin]

Originally Posted by a64pilot

I'm bad about letting out pretty much all of the rode at once and letting the boat drift back, usually with the main still up and backwinded, a CQR would just slowly bring me to a stop as it drug, the Rocna digs in fast and there is no drag to a stop. Once that rascal hooks and jerks the bow around I feel as long as the weather is good, I'm set.

This gets right to the OP's original question; pretty much everyone who describes new-gen anchors setting hard and fast are speaking from experience with old-gem anchors. It's all relative, all other aspects of the process being equal.

My CQR sets slowly, digging in and gradually plowing to a stop. My Rocna grabs much more quickly.

I generally stop the boat dead in the water, walk forward and drop the anchor and pay out rode as my boat is drifting slowly down wind/current. I let out @ 3:1 scope, let her grab, then ease the boat into reverse and gradually increase revs up to maybe 1/3 throttle (Maxprop is pretty aggressive in reverse) and dig it in. My CQR will usually plow a bit, depending on the substrate, but the CQR is as I've said before usually like hitting a brick wall. It's relative. And this is with a snubber, which doesn't really have enough stretch to hide the differences between the two, even with 20' feet out.

Anyone who doesn't back down on their anchor is not likely to feel the difference unless there's a considerable current or wind blowing.

I'll say it again for the OP's benefit, even though I know there is disagreement on the subject; if you don't back down on your anchor you don't know how well set it is. All you know is that it will hold you in the existing current/wind, and that's a pretty tenuous level of security at best.

[thinwater]

My anchor has never drug, although it has dragged.

I'm surprised at the number of respondents that say the chain jerks (or something equivalent), but not one person mentioned how they secured the chain to prevent the windlass from taking the hit. My presumption is that most of the respondents allow the windlass to take the hit, for better or worse. In a protected harbor the jerk is not that noticeable and there is probably no more load than when they break the anchor out in the morning. In fact, the main reason I put the snubber on before the slack is out is to avoid this jerk. If I am going to back down anyway, I don't understand what purpose it serves. Unlike backing down, it is not quantifiable.

You won't feel a jerk in very soft mud.

I took the chain off my Fortress and now use an oversize Dyneema leader with a chafe guard.

• Since I only use it as a secondary anchor, there is no yawing back and forth. It is also not my sole anchor in this situation.
• I wouldn't be using a Fortress in coral or rocks.
• It is much easier to handle on deck and much easier to row out.
• It is easier to recover. No risk of the chain scraping the top sides.
• You are more likely to use something that is easier.
• The rode is thinner, allowing the anchor to set faster.
• Chain and settling actually inhibit the setting ability of Fortress anchors in soft mud. This is on their web sit and it is obvious; the chain and shank sink faster than the flukes, resulting in a fluke-up posture. A lighter rode sets faster.
• Yes, in a strong current chain will help the anchor get down faster, but if there is a fast current, the bottom is not soft mud. I would add chain if I were anchoring with 2 anchors in a strong tide.

This sounds "risky" when compared to conventional wisdom (pre-Dyneema), I suppose, but is an over size Dyneema leader with a chafe guard more prone to cutting than nylon 10-20 feet farther up? No, laughably not.

[Suijin]

Originally Posted by thinwater

I'm surprised at the number of respondents that say the chain jerks (or something equivalent), but not one person mentioned how they secured the chain to prevent the windlass from taking the hit. My presumption is that most of the respondents allow the windlass to take the hit, for better or worse.

Whut???

A few of us did, and regardless I think it's a pretty suspect leap of logic to conclude that where there is no mention, there is no use.

I always use a snubber. My chain is never directly loading the windlass, unless the snubber breaks or comes off the rode. If conditions merit it, I'll rig a back-up snubber too.

I have a $5k windlass. I'm not going to subject it to shock loads it was not designed for, ever, if I can avoid it. Split gypsies, glazed clutches, broken gears, etc. It's just not a good idea.

[thomm225]

I can make my CQR jerk the boat if I want by cleating off the line with the boat going too fast

I'm thinking it has a lot to do with the bottom you are anchoring in.

So far I've had good luck with the CQR here not dragging......and I don't back down

Maybe I'll need a new gen anchor one day but so far the old worn, beatup CQR that came with the boat is doing the job, but then I've mostly always had old anchors when on the bay since the 70's.