Anchor Dragging Story (long)

[BruceK]

Surely plow/plough comes from the tractor(previously horse)drawn implement with multiple wedge shaped furrowing devices, used to prepare fields for crops. Translates easily to CQR and similar types. But the Super Sarca is entirely different.
Absent the organ grinder, the monkeys do their best.

 

[BandB]

We do have Delta's and they're most common on larger boats. The point of my question wasn't to argue the merits of anchor types, just that a 55# Delta was on the boat when he bought it. So, my question was why he didn't just use it instead of the 45# Manson. When he reinstalled the Delta, it held fine for him.

I'm not an anchor expert. However, each of our boats has come with an anchor and we've used the one it came with. I'd certainly do so until I was sure of a better choice. One thing we often advise here is to use the boat a while before making big changes. Well, I'd include the anchor in that.

 

[BruceK]

...One thing we often advise here is to use the boat a while before making big changes...

I what context do "we" have the opportunity to give that advice?

 

[BandB]

I what context do "we" have the opportunity to give that advice?

I've just seen many post that to new boat buyers who are thinking of all the upgrades they want to make. I used the word "we" as collective for the forum but not meaning we all do so.

I was just curious on the anchor, nothing more. Good anchor came with boat, switched to bad undersized, back to good which worked, now to another new anchor.

 

[Nomad Willy]

I'd say the 45lb Supreme should outperform a 55lb Delta just looking at the anchor tests over the years that had both on the test. The Supreme is a higher performing anchor.

 

[kev_rm]

Interesting article. I find it a convincing argument under extreme conditions where the wind and current would completely straighten the rode.

However, I don't find myself in those situations. I do find situations where I have to use less scope than I might like. In that situation, the heavier chain does provide some more catenary and its improved shock absorption and improved shank angle.

I would be interested to know specifically what force would be required to fully straighten 100' or more of chain with significant scope...

my instinct lifting the the last 20% would be many many tons.

 

[BandB]

I'd say the 45lb Supreme should outperform a 55lb Delta just looking at the anchor tests over the years that had both on the test. The Supreme is a higher performing anchor.

It wasn't that night in those conditions.

 

[Nomad Willy]

BandB,
Are you say'in all the tests are fake news"

 

[BandB]

BandB,
Are you say'in all the tests are fake news"

No. I'm not going into politics here nor am I asking for an opinion or expressing one. I'm dealing with real world of what happened with the OP and I've asked him, not you, him why he chose not to use the 55# Delta that came with the boat. Immediately casting it aside for a smaller unit of another type just brings that question. I'm not after your anchor expertise, but rather his reasoning.

 

[Peter B]

As I understand it...

Rex disputes all that, at least for his anchors. He also argues his anchors with convex flutes are not plows.

Except he spells it ploughs.

-Chris

Glad you brought that point up, Ranger, because it's the only thing in Eric's post I really disagree with, but it is a very commonly held misconception. I know Marin used to be fixated on this issue.

The word plough (or plow if in the US), is used loosely to describe the so-called convex shape, but in reality is quite wrong, because a true plough is a single curved blade, designed to do nothing else but present minimal resistance to pulling through the ground (otherwise a horse could not move it), with the entire intent to turn the soil over to form a furrow.

The convex anchor fluke is actually like two of the blades of a plough in mirror image joined down the upper edge, and produces an entirely different effect. It does shed substrate better than the concave fluke, true, (especially when coming up, thank goodness), but the benefit from that is that it tends to not get clogged, which then potentially can prevent a quick re-set on a change of pull direction. But also, if pulled through the substrate, in this case the bottom, not the soil in a field, the net effect is for it to tend to dive down even deeper, while at the same time not gouging a huge furrow in the sea bottom - good for the environment, best seen if you imagine looking at the fluke from the pointy end, and coming towards you. The tip is lower than the shank end, and the bevelled effect of the two sides essentially turn it into a shape like a dart with no lift. If you made a dart that shape and threw it, it would dive straight for the floor. That's the best way I can think to describe it's NON-PLOWing action.

Which is why I agree with this comment of Eric's...

But when you pull the (concave) anchor up sometimes (or frequently depending on where you anchor) there will be a big heavy ball of mud stuck fairly well to the fluke. PITA.

but strongly disagree with this...

The convex fluke sheds the substrate a bit like rain on a roof. The substrate readily tends to sluff off the fluke, to the side of the anchor (disagree especially this) doing little to hold it down.

 

[Nomad Willy]

Good post Peter,
Quote Peter .. "The convex fluke sheds the substrate a bit like rain on a roof. The substrate readily tends to sluff off the fluke, to the side of the anchor (disagree especially this) doing little to hold it down."

Yes I should have taken more care to write that one. The substrate does tend to slide or/and be pushed sideways but what I failed to mention was that it meets heavy undisturbed seafloor on each side that is not easily displaced.
But I think my point of convex anchors move substrate to the side whereas scoop anchors tend to push or lift it up may be worth thinking about. So during the initial deployment/setting there may be as much resistance pushing aside as pushing up where at that time there is little substrate above the scoop fluke and more alongside the flukes of the Delta style anchor.
But the SARCA has so little convex angle (really closer to flat) to its fluke that in this regard is much like a scoop anchor as opposed to a Delta/CQR style anchor.
But "rain on the roof" was definitely not even a half good analogy ..sorry.

 

[Montenido]

Hi folks,

B&B, you raise a valid question, "why did I not just use the 55# Delta that came with the boat?". Well, that would at least partly be because I am an idiot. The original anchor both fits well on the bow, AND seems to hold the boat fine in heavy conditions. For some reason I had it in my head that a new generation anchor would be safer. (If it ain't broke...).

Well, now I have two 55# anchors, the Delta and the Rocna. Since the Rocna is installed already, I will use that for now and see how it works. The other anchor is in my rear lazarette, so I can always switch back. What makes my whole dragging story even more painful, is that I caused it by installing a marginally-sized anchor in place of one of appropriate size.

Sometimes I do stupid things, and I think this qualifies as one of those times. Regardless, I think that my story opened up some great conversations about anchoring techniques and tackle, and I thank you all for participating.

Cheers, Bill

 

[BandB]

Hi folks,

B&B, you raise a valid question, "why did I not just use the 55# Delta that came with the boat?". Well, that would at least partly be because I am an idiot. The original anchor both fits well on the bow, AND seems to hold the boat fine in heavy conditions. For some reason I had it in my head that a new generation anchor would be safer. (If it ain't broke...).

Well, now I have two 55# anchors, the Delta and the Rocna. Since the Rocna is installed already, I will use that for now and see how it works. The other anchor is in my rear lazarette, so I can always switch back. What makes my whole dragging story even more painful, is that I caused it by installing a marginally-sized anchor in place of one of appropriate size.

Sometimes I do stupid things, and I think this qualifies as one of those times. Regardless, I think that my story opened up some great conversations about anchoring techniques and tackle, and I thank you all for participating.

Cheers, Bill

Thanks for answering. It wasn't at all stupid. You are definitely not an idiot. It was as I suspected. If I believed everything I'd read about anchors on this forum, I'd be tossing all mine today. It's humorous sometimes that those who criticize new technology, electronics, etc. then are the same against all the traditional anchors. We all need to be careful. There are more conventional, old school anchors in use, working well, than any specific new generation anchor. In some cases they work simply based on extra weight. Look at large vessels and it's not the style of anchor, it's the sheer size of the ones being used. All the different types have really targeted smaller recreational boats and one thing they all claim is more holding power for the weight, but all have limitations in certain conditions. As I suspected, you were scared away from an anchor before ever trying it, simply based on what you heard.

Our anchors all came on the boats, matched by the manufacturers, and are on many other identical boats. I know, at least partly, they work well because by most tables they're oversized. However, they work. We only have newer anchor types for backup, stern anchoring, and on the center console which is never anchored overnight. On it, minimum weight of anchor was then a factor.

I honestly have no idea which of the new is best for what and I'm not sure anyone does with all the conflicting information. I believe that they all are better at one thing or another than old style but also each has a weakness. We use windlasses so weight isn't an issue. If it was, i'd be perhaps rethinking it.

I'm sure you heard how great new style was and then how you could reduce weight. Perhaps you picked up bits and pieces of information. Regardless, it all led you to reject something that had worked for the prior owner, installing something that didn't work for you.

I'm not putting down the science or all the new designs. I do think we sometimes do harm though in making all the old styles sound far worse than they really are and making people who have anchors well matched to their boats, think they are in danger and must get a different type anchor.

We, the boating public, TF, those at the dock...the collective "WE" are the ones who led you to make a mistake.

 

[Nomad Willy]

Good post BandB,

You wrote;
"It's humorous sometimes that those who criticize new technology, electronics, etc. then are the same against all the traditional anchors."

Sounds like me but do'nt recall being critical of traditional anchors .. not as a group but I have been critical of a wide range of anchors. Both old and new.

 

[BandB]

Good post BandB,

You wrote;
"It's humorous sometimes that those who criticize new technology, electronics, etc. then are the same against all the traditional anchors."

Sounds like me but do'nt recall being critical of traditional anchors .. not as a group but I have been critical of a wide range of anchors. Both old and new.

In your case you are critical of every anchor in some way probably because you know all the strengths and weaknesses. As to you being critical of traditional, perhaps just promotional toward new. I don't think you've ever told anyone to throw their Delta overboard.

I don't profess the knowledge of anchors you have. Many of the anchor discussions though would leave a newbie thinking no anchor was adequate and they absolutely must go buy a new one, probably two or three or more, just to have one for each bottoml type they might encounter.

Boaters at the docks and boater forums (which are just enormous amounts of dock talk) often can leave frightening impressions. Soon you end up thinking all anchors but the latest are lousy. All boats except Nordhavn or KK are unsafe. How many times have we all heard Bayliner and Mainship put down. Yet, we know how many extremely satisfied owners they have. Volvo is a target. An easy one because not a lot of volvo's represented on the docks or forums. So people who have never owned one tell why they never would, that it's impossible to get parts or get serviced. It's not. In some areas it might be more difficult. However, Volvo has a tremendous following for it's engines in Europe. We have many happy Volvo owners here. Pods is another hot button topic and if you read some discussions you'd think they're the worst idea to ever come along. You'd also think the concept was reason. Well, pods have their places and they have many happy owners.

Same thing on electronics and equipment where if you listened to some you would think it's all going to lead to a miserable existence.

None of this is really absolutes and sometimes we all come across as presenting it as such.

Oh, and for the record, I'm the opposite on the anchors and technology. I want every bit of modern technology I can find and I'm perfectly happy with my old style anchors and none of the more recent types.

 

[foggysail]

Summary:

Go with BIG modern anchors!

Experience:

I am one of those boaters that own a Silverton 40 aftcabin that is comfortable and satisfies our needs. It provides the comforts of a small condo and allows us to travel to many harbors. So no complaints here pertaining to boats that lack pedigree papers.

Now onto anchors! We started boating back in 1979 with a Hunter sailboat...no windlass. We found the Danforth that came with the boat purchased new to have problems although I do believe a larger one may have been sufficient. So I moved up to a Bruce 33# (later to a 44# with no performance differences) that worked extremely well for all our anchoring. We anchored just about every week during summers. That all came to an end when our harbors filled with ell grass. From that point on, Bruce was untrustworthy for us. It gave a sense of being secured but tugging on it would lift a chunk of ocean bottom where it used to hold tightly.

Moving onward to our Silverton! Mr. Bruce (44#) could and did hold in sand but only in sand. So I moved to a 55# Delta. Now my nightmares really began. Our boat slipped every time we anchored in either tidal currents or wind. The slip was slow, never the less.........we slipped! So I thought that an 88# Delta would do what the 55# would not. Not so! WE COULD NOT LEAVE THE BOAT UNATTENDED! We use 5/16 HT chain rode with the Silverton.

Yes.... I am criticizing the Delta anchor's performance based on experience! And yes again, it is an older style anchor design! So again I moved onward and purchased another big bucks replacement, an 80# Manson Supreme. And that anchor has its problems also as I found out in a wind change situation but it at least held under other occasions where Deltas would not. Our future will see the Manson backed up with a Fortress FX55.

Foggy

 

[Nomad Willy]

BandB wrote;

Boater forums which are an "enormous amounts of dock talk"
I love it. So spot on.

"Soon you end up thinking all anchors but the latest are lousy"

Too often probably true. Most newer anchors are probably better than they need to be. But the bottom keeps sneaking up on us.

Another great post. What have you been eating?

 

[Moonstruck]

Once we were anchored in the Bahamas. I deployed my Delta anchor. All seemed well. We were settled into the cockpit chairs enjoying drinks and snacks when it was noticed that we were drifting toward shore. I got up, pulled the anchor, and we pulled the boat out to reset it. I got in the dinghy to check the anchor with by lookie bucket. All looked well. We dragged again. So, I dove into the clear, warm waters to swim the anchor. It looked like it was set well, but underneath the shallow sand was fairly smooth shelf rock. As the boat would swing it would pull the point out of whatever little groove it had caught on. No amount of scope would help that. We anchored in another location.

This is just another possibility of how bottom conditions can affect anchoring.

 

[Peter B]

B&B, you raise a valid question, "why did I not just use the 55# Delta that came with the boat?". Well, that would at least partly be because I am an idiot. The original anchor both fits well on the bow, AND seems to hold the boat fine in heavy conditions. For some reason I had it in my head that a new generation anchor would be safer. (If it ain't broke...)....
Sometimes I do stupid things, and I think this qualifies as one of those times. Regardless, I think that my story opened up some great conversations about anchoring techniques and tackle, and I thank you all for participating.
Cheers, Bill

Good rule that..."If it ain't broke..."
Bill, thanks for being so honest, but be assured, no-one on here would think you are an idiot, and I think you were a little hard on yourself in saying that. But honest, yes, and as a result you started a thread which will certainly have benefitted any who followed it.

Actually, I believe that but for the freak of striking those conditions in that place, which exposed the perfidy of a soft sand bottom, you would still be happily using your then new 45# Supreme. If I'm in for a blow, give me weapons grade mud every time. I'm happy to hose it off - anything but soft clean sand.
But never mind...you did get caught out, and your experience, which you bravely shared, underlined for us all the wisdom of the common sense rule of getting an anchor that's about right for the vessel, then going one size up. It works.

As to the reason the Delta is best left in the lazaret, well that's illustrated well by Foggysail's experience in post #76, and is because it is a shape that is rather too convex, such that with a good force on it, it will submarine along under the substrate. Its saving grace is that it drags slowly, and seldom suddenly lets go. However, bigger size helps compensate, as the PO of your boat found.

 

[markpierce]

In my mind, plow-like anchors are a poor excuse. Plows are designed to turn over earth and not to make it overly difficult to pull through the ground.

 

[Peter B]

In my mind, plow-like anchors are a poor excuse. Plows are designed to turn over earth and not to make it overly difficult to pull through the ground.

Mark, might I suggest you read my post 70, above...carefully...

 

[ranger58sb]

Our anchors all came on the boats, matched by the manufacturers, and are on many other identical boats. I know, at least partly, they work well because by most tables they're oversized. However, they work.

I can imagine that some boat/anchor matching by boat manufacturers can be driven by less useful factors, like cost and so forth.

Boat manufacturers can't easily predict what bottom types might most apply to buyer X, so they likely pick an anchor that will perform generally well in all substrate. "Generally well" can be OK for some, not so OK for others (our mud up here comes to mind).

And then there's that size thing. Our current boat was apparently fitted with a Delta anchor two sizes smaller than I would have picked. There was no electric windlass installed (???) so maybe that anchor size was influenced by the thought of an owner doing manual lifting... but I'd guess it was more likely just a cost-minding choice.

And boat design, especially pulpit/roller design, can control the manufacturer's decision, too. No roll bars for us (so to speak, probably) because our slot-thru pulpit won't work with a roll bar anchor (at least at first glance; haven't measured closely). Had the boat maker designed/installed a different kind of pulpit or other anchor system, they might in turn have had more options for whatever anchor they chose to include when the boat was new.

Bottom line, I guess, is that I think it makes sense for a new boat owner to question the boat manufacturer's choice... not as a knee-jerk to dock talk (or forum talk... but rather as a sensible approach that can take into account that new owner's specific circumstances.

Once we were anchored in the Bahamas. I deployed my Delta anchor. All seemed well. We were settled into the cockpit chairs enjoying drinks and snacks when it was noticed that we were drifting toward shore...... It looked like it was set well, but underneath the shallow sand was fairly smooth shelf rock. As the boat would swing it would pull the point out of whatever little groove it had caught on. No amount of scope would help that. We anchored in another location.

This is just another possibility of how bottom conditions can affect anchoring.

Yep, sounds like one of those cases where it wasn't the Delta's fault; could have had the same results in that specific spot with most any anchor design.

-Chris

 

[Nomad Willy]

Mark,
Indeed. Minimal resistance and maximum disruption.
But if the resistance is low the door is open (likely) to good penetration that could result in more than a bit of good holding power.
I anchored in the end of a small inlet w two other boats during a 50 knot gale. The Krogen 42 w a Bruce tangled in a small tree dragged almost into us. We were forced to re-anchor. The big forty something foot sailboat did'nt drag at all (that I could see) and I saw clearly that they were using a good sized CQR. The plow of plows.

 

[BandB]

Bottom line, I guess, is that I think it makes sense for a new boat owner to question the boat manufacturer's choice... not as a knee-jerk to dock talk (or forum talk... but rather as a sensible approach that can take into account that new owner's specific circumstances.

I agree with that, perhaps even discuss with the builder. We're fortunate that we've had builders who didn't shortchange there. Our boats are not unique and there have been a high volume of each built so a history established.

I'd just suggest giving it careful consideration but as you say not just changing because of something you've heard or read "somewhere."

 

[Benthic2]

This was a very interesting thread....

However...no one brought up weather monitoring. Staying on top of the weather is kind of key to all aspects of boating. Its all well and good to have lengthy discussions on anchor scope and convex vs concave anchor surfaces.....but having a gale force wind sneak up on you should be of greater concern.

 

[Peter B]

This was a very interesting thread....

However...no one brought up weather monitoring. Staying on top of the weather is kind of key to all aspects of boating. Its all well and good to have lengthy discussions on anchor scope and convex vs concave anchor surfaces.....but having a gale force wind sneak up on you should be of greater concern.

Fair comment, and worth reminding, but I suspect for the majority on here, taking weather into account is a given any way. No-one willingly exposes themselves to a night of anxiety, no matter how confident of their gear they are.

 

[BandB]

Fair comment, and worth reminding, but I suspect for the majority on here, taking weather into account is a given any way. No-one willingly exposes themselves to a night of anxiety, no matter how confident of their gear they are.

A given. Should be. However, we still see people all the time caught out in conditions that were clearly indicated 12-24 hours earlier. It's not just cruising either, sometimes just anchoring.

 

[sunchaser]

A given. Should be. However, we still see people all the time caught out in conditions that were clearly indicated 12-24 hours earlier. It's not just cruising either, sometimes just anchoring.

I have found that boaters who stray far from the docks are pretty weather alert.

 

[BandB]

I have found that boaters who stray far from the docks are pretty weather alert.

There are regularly rescues that indicate though that some are not. Those are the ones who need reminding.

 

[bayview]

ding, Ding we have a winner

I am guessing 5', giving you a vertical height of 17'. With 100' of chain out, you had a scope of under 6:1.