Anchor size, big is better?

markpierce said:

Don't you think their owners would have changed anchors if they didn't work?

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I read somewhere credible that 90 percent of recreational boaters never anchor out. So it doesn't really matter what they have on their bows.

Marin said:

I read somewhere credible that 90 percent of recreational boaters never anchor out. So it doesn't really matter what they have on their bows.

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Is that why some have stainless steel anchors? Anchors are eye candy? No SS anchors at K dock, however, except for a Delta or two.

My neighbor has a Bruce and a CQR on his GB-42 bow (I've only a single claw on the bow), and anchors regularly. But as I said before, the sticky, heavy mud of the San Francisco estuary is kind to anchors. ... Marin, you continue to be in denial regarding people selecting anchors other than your own. Regardless, I'm glad you have an anchor you trust.

markpierce said:

Marin, you continue to be in denial regarding people selecting anchors other than your own. Regardless, I'm glad you have an anchor you trust.

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Boaters can select whatever anchor they choose. It's nothing to me. We had our original anchor fail us too many times so we went in search of a replacement that would work better and we found one. So far it's worked perfectly every time.

If someone else uses a Bruce and has good luck with it and thinks it's the greatest anchor on the planet that's fine with me. I'm not going to tell them their choice is wrong. If it fails them one too many times they'll figure that out on their own and do whatever they do to remedy the situation, just as we did. If it never fails them, well, they won't have to go in search of something better.

I've just been relaying what our experience was, why I think we had that experience, and why we would never choose that anchor for any boat of ours again. Other people's experience has no relevance to ours, just as ours has no relevance to theirs.

Marin said:

Peter-- I don't think the convex fluke of the Sarca is convex enough to make all that much difference. By "streamlined" I was referring to the CQR.

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Ok, just for the fun of it, let's explore this 'streamlined' in the direction of pull, issue a bit more. Marin, I thought with your aeronautical background as well, you would have this all figured, (as relates to laminar flow over a surface), but for the sake of argument and exploring why things work, let's take the old trusty CQR as an example.
Yes, I ditched one because it failed me too often in the places I like to anchor, but as others have said, it has lasted well, not only because it sits well on a bowsprit, but because of its shape. if you get the damn thing to set - which it does really well in very soft bottoms - then it digs in well.

Why...precisely because of the 'streamlined' shape you don't like Marin. Marin, you made the comment..."Plows are designed to move through the soil, pick it up, and move it to the side. If they didn't work that way, the horse would stop."
Absolutely right. The difference being, when one refers to the plow type, as it is often called, (actually we spell it plough, but never mind), it is an approximation, is it not? Actually, a plow-share is not really like a plow anchor fluke, it is like half a plow anchor fluke. In other words a plow-share is one curved and angled blade, as if you cut a CQR fluke down the centre, and that, added to the fact the plow is supported on a frame and wheels, which stop it digging in too far, is why the horse can pull it. The soil is merely scooped and shed to one side. However, if you add the mirror image blade, thus forming the classic (plow)CQR, (and Delta, and even the S, Excel, and, although a shallower convexity, the Super Sarca, convex fluke shape), one ends up with a shape which does want to dive down and keep doing so, as long as the tip engages...thereby being the weakness, if you like, of the CQR on firmer or weedy bottoms.

If we then go back to the horse and plow, and place plow-shares on it with both sides forming the classic V shape like the flukes of the anchors above, and remove the wheels, then it would dig down very quickly to a point where no horse could move it...
In other words why that shape simply works...
My case rests.....and to give a balanced view...

Marin I think Peter man has got you good. I just didn't think about it. There are good reasons the farm plough dosn't burry itself. And an anchor that isn't streamlined will NOT penetrate the bottom or go very deep. I always thought the Claws were TOO streamlined and that was the simple explanation for their reputation to drag in soft mud. Many anchors have stocks and roll bars ect that impede progress through the bottom and do two things;
1. They resist movement and thus give a bit of holding power to the anchor.
2. They drag their very non-streamlined shapes through the bottom and prevent the anchor from penetrating deep enough to have serious holding power. And since roll bar anchors are probably tested in substrate soft enough to penetrate deep enough to have serious holding power they do well in the tests.
An anchor like the Delta, Excel and Spade don't have any appendages sticking out to get in the way of progress downward and thus, I believe, are serious penetrators with serious holding power w less size, weight and fluke area as roll bar anchors or anchors w stocks. But anchors w the shape of these three typically come up a bit short on short scope holding power in many of the anchor tests I've read. Of course if a roll bar actually does go deep in the ideal bottom the roll bar itself adds significantly to the holding power but is still not the ideal shape to make maximum holding power. So holding power of roll bars and stocks is rather low. On a Danforth (the highest holding power anchor on earth) anchors there are stocks and skids that aren't part of the flukes but they don't come into play until the flukes are buried.
So I think the ideal anchor (holding power wise) should have a short, light and streamlined shank w a large slightly concave and light fluke of great strength. It's hard to get weight out of the picture as it's so important for setting. The Oceane anchor by Spade is such an anchor but has setting problems in all the tests.
As to convex look at the Delta and the Excel. They are VERY convex. But they are both high holding power anchors. So the fact that a convex surface has more resistance is practically meaningless compared to other aspects of the anchor design. Like the 2 big flip up surfaces aft. The combination of cleanliness or slipperiness to go down being minimized and the resistance to coming up being maximized should result in the best anchor if (big if) it can dependably penetrate the bottom. W/O these two big if's these 2 anchors and the Spade are about as optimal as can be. My XYZ would even be better if one could get the attach point ideally further aft but it wouldn't set and it wouldn't come back up in the morning.

So Marin is undoubtably right that concave fluke anchors can work very very well. And the very slightly convex fluke of the SARCA is fly stuff re this issue.

I wonder what the difference in throat angle is between the Excel and the Delta?

I have understood the principle behind the CQR from the moment I first saw one. I know why it digs down and I know why it's supposed to "stop."

My dislike of the design compared to anchors like the spade, Bruce, Rocna, etc is that under a high load, and particularly in a less-than-firm bottom, where the other anchors "pile up stuff" in front of them which can help add to their resistance to the pull, the CQR is pointed in the direction of the pull. The angle of everything on it is aligned to move through material, not pile it up in front. It's why shovels don't have blades that look like CQR flukes.

So, if the amount of pull and the consistency of the bottom combine to defeat that "aerodynamic" principle that causes the opposed plowshare design to dig deeper, it's beautifully set up to do what the design was originated to do--- dig a nice straight furrow with the boat in the role of the horse.

Obviously this doesn't happen with great frequency or the anchor would have quickly fallen out of favor. But it can and does happen and to me the design is set up to cave and start plowing insted of piling up material in front of it and doing everything it can to resist movement. So I eliminate the risk by not having the anchor.

Marin the non-burying types like my Dreadnought and the Navy anchors are quite another story. When a Navy anchor plows up a big pile of sand or whatever in front of it in a big way that pile acts like the bottom piled on top of a modern anchor and in a real way can be sort-of considered the weight of the anchor.

Burying and non-burying types are like planing and disp hulls. Way different.

Bigger is better

Delta is a plough anchor, slight difference in its plowing action as to a CQR but never the less a plough, Excel, Super Sarca are not, as I have stated many times, when we design our anchors extensive research goes into their design as our anchors have been developed for a wide and variable industry.

For interest, NRC of which has been disappointing, the up side to this, the pallet of anchors they purchased from us were on trial for holding oil spillage booms, were they successful, well we have more going off to them in the New Year.

This is another example of what I mean when I say our anchor designs do not only cater for a section of the marine industry, this was very much part of the thinking during testing and development.

The link I have inserted is confronting and clearly shows the argument of concave convex and plough as in plowing design, take particular notice of the shape of the trench behind the various designs it tells you a heck of a lot.
Whether or not you think the various designs will hold better or not that is for you to debate forever.

If this is seen to be commercialization on your forum the link may be pulled. It is purley an attempt to assit you with your discussions. Next Generation Anchor Environment Destruction - YouTube
If it is pulled and someone is interested you can find it on our web site UNDER ENVIROMENT DESTRUCTION.

Marin you yourself stated the makers of your design recommend five to one with all chain, again try telling this to trailer boa tie or fisherman operating in 70 meters of water, his little boat would sink with the weight, (all chain) our commercial customers who operate on the continental shelf will tell you letting out a Kilometer of rope is not uncommon.

What does your anchor designer recommend for the same applications?
Five to one is overnight anchoring I am a firm believer for reasons I have stated, it doesn’t mean you can’t anchor on less and have never said that. ( five to one is a common proven safety scope)

Regards.
Rex.

CEO of Anchor Right Australia.

Rex; said:

What does your anchor designer recommend for the same applications?

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I have no idea. It's not a type of anchoring we'd ever do so it wasn't anything I had any reason to enquire about. They gave me their recommendation based on the kind of boat we had and the kind of anchoring I said we were going to be doing.

I assume that for the deep-water people they would do the same as any anchor manufacturer and either recommend a rode and ratio more suited for that type of anchoring or say nothing at all and leave it to the fisherman or boater to come up with their own solution.

Rocna seems to be aware of the fishing market--- they introduced a smaller version of their anchor with a slotted shank marketed specifically for fishermen who change locations frequently during a day of fishing and who fish over bottoms where snagging an anchor is a real possibility. It's the one application of a slotted shank that makes sense in my opinion. I don't know if they still offer this anchor as the company has changed hands a couple of times recently.

If we should find ourselves having to anchor in deeper water than we have so far we sized the 300' combination rode for our stern anchor to be the main rode for the whole boat. Actually the stern anchor itself (Fortress) is sized to be the main anchor of the boat. Its rode is kept in a box on the aft deck so we could carry it forward and shackle it onto our 200' of all-chain rode if we needed more to get the scope we wanted. So far we've not had to do this.

Bigger is better

Marin wrote;

I have no idea. It's not a type of anchoring we'd ever do so it wasn't anything I had any reason to enquire about. They gave me their recommendation based on the kind of boat we had and the kind of anchoring I said we were going to be doing.

I oppolgize Marin, Ithink that was a silly question.

Regards.

Rex.

Ceo Of Anchor Right Australia.

I don't think so. Someone needing to anchor in deep water for whatever reason--- fishing or because the water where they boat is often very deep as it is up the BC coast and in SE Alaska--- would probably be interested in what Rocna or any other anchor manufacturer had to say on the subject. I just don't happen to know.

Interesting Rex,

But I see almost no difference between the Delta and the Excel. Look like both are Plow anchors to me.

Watching the video I really like the way the bottom that the SARCA lifts up goes neatly and gracefully through the roll bar opening and back to the sea floor. That has big plusses as to conservation but I think it also permits the SARCA to spend less effort messing up the surface and going deeper. Just an armchair projection though.

Re the difference between the Delta and the Excel I'm wondering if the Excel has a wider throat opening. If I was to buy a Delta I'd be tempted to shorten the shank about 3". If I was to shorten it 5 or 6" I would be concerned that setting may become difficult as the fluke tip would become slightly less parallel to the direction of travel while the anchor is being set. Shorten it enough and the fluke would be at right angles to the direction of travel. Comments?

Bigger is better

Ithink you had better take a closer look Eric,the Delta turns over the substrate--Plowing-- the Excel clearly lays the substrate same side up.

Throat opening -- never should any one change alter an anchors design unless they have designed it themselves , that is the best advice I can give you, all anchor designs performance has many of key innovations that will never be picked up by the eye, enven the little one percenters when all put together make it happen , not much different to people, if you got the wrong DNA YOU CAN BE A BAS---D OF A thing all there-- its life and no modification or learning will improve either.

If it was all that easy it would not have taken 5 years of frustration-- determination, and yes our design to have been called a lot wers than a bast---d of a thing many times.

Remember you are tinkering for your self, we are tinkering for you, big difference.

Regards.

Rex.

CEO of Anchor Right Australai.

Eric, my primary anchor is a Delta. Secondary anchor is a Danforth. I usually do not anchor in water over 30' deep. In fact it is usually much shallower than that. Because many places we anchor are in gin clear water, I can snorkel and dive the anchor most times. Just to double check everything. I usually can also check it with my "lookie box" from the dinghy. Use 30' of chain and the rest 3/4" twisted nylon rode. I will not say that it sets instantly, as there are usually some tracks. It does set quickly, and will hold a hard pull of the boat. We usually use a 5 to 1 scope. If windy 7 to 1. Stormy 10 to 1.

Here we are anchored at Rodriguez Key in the Florida Keys. About 7' of water.

Bigger is better

Best way to compare each design is to hit the pause button when they rear view comes up on the comparisons.

Regards.

Rex.

CEO of Anchor Right Australia.

OK Rex I see it. The shank seems to be attached more fwd on the Excel and the Delta's trailing edge probably flips the bottom a bit up in the air whereas the Excel allows the bottom to slide over the trailing edge kinda like the SARCA.

I'm not saying I'm going to or not going to modify any more anchors. I did that to an XYZ because the manufacturer would'nt sell me a nose piece ... so I made my own and I made it quite different. In the pics the pointed one is the original XYZ and the blunt chisel nose is mine. It worked flawlessly on a 1000 mile 33 day trip and I used it over half the time. So my track record on modifying anchors is perfect (so far) but I know I didn't find anything but a soft bottom each time I anchored w the modified XYZ as I feel quite sure on a hard or rocky bottom it probably would not set. And I'm sure you'll agree w me. But ..... anchoring is full of surprises.

By the way this is the anchor I was talking about w the heavy trailing edge that can transfer downward force to the "toe" to assist or facilitate setting.

What I'd like to know is does the throat angle affect the setting performance more or the holding performance? I haven't got any tools out here Rex ..... just armchair engineering w a non-engineer. I would imagine a wider throat angle would enhance short scope holding power. Basically I think that's what Fortress and Super Max anchors do their adjustable throat angle.

Marin said:

I have understood the principle behind the CQR from the moment I first saw one. I know why it digs down and I know why it's supposed to "stop."

My dislike of the design compared to anchors like the spade, Bruce, Rocna, etc is that under a high load, and particularly in a less-than-firm bottom, where the other anchors "pile up stuff" in front of them which can help add to their resistance to the pull, the CQR is pointed in the direction of the pull. The angle of everything on it is aligned to move through material, not pile it up in front. It's why shovels don't have blades that look like CQR flukes.

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That's because when you are using a shovel, you are wanting to dig out dirt, whereas with an anchor you want it to dig deep, but not bring up half the bottom - well that's what I want anyway. If you want to really dig deep you use a pick, right? Sharp & pointy. If you are securing a tent you hammer in tent pegs, not shovel shaped things. In other words, deeper is better...not wider.
Anyway, enough of that...this question of scope length is an interesting one. I think in deep water 3:1 is more practical and quite effective for two reasons - what ever the type of scope used the catenary is pretty high just because of the amount out, and the resulting vectors make the pull transmitted to the anchor correspondingly less.

The second reason is, let's face it, if you are anchoring in really deep water, then the bottom is far from your keel, so if you did drag a bit..so what? Unless you are in a rather weird place where the edges shelve really steeply, like a fjord or something, which is a pretty silly place to anchor anyway. So, if you did drag, (in a deep anchorage) it would probably not be far enough to matter, given reasonable room.
What say you Eric..Rex..?

Peter B said:

That's because when you are using a shovel, you are wanting to dig out dirt...

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No, when I am using a shovel I want it to capture and hold dirt, not shed it off the sides. Digging out or digging in, that's irrelevant. What is relevant is how that blade, or fluke, acts on the dirt. A plow moves it aside, a piece of metal 90 degrees to it resists moving through it. Simple physics or geometry or whatever it is.

Stick your hand out the window of a moving car and hold it flat or even at a bit of an angle. No resistance. Turn your hand vertical, all sorts of resistance.

Under the right, or should I say wrong, circumstances an anchor with flukes angled to shed the bottom when it moves in the direction of pull is self-defeating. An anchor with flukes presenting their full width in opposition to the pull is not.

Have you watched the Video Marin, up there in Rex's post...?

Yes.

Peter B said:

...if you are anchoring in really deep water, then the bottom is far from your keel, so if you did drag a bit..so what? Unless you are in a rather weird place where the edges shelve really steeply, like a fjord or something..

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Peter,if you know for sure the worst scenario is dragging "a bit" (a malleable term), then just maybe it is tolerable, but once you drag you drag, it may or may not reset,you may or may not be asleep or otherwise occupied, you make wake to a resounding crunch. Anchoring mid ocean is rare, it`s usually near that pretty bay shoreline. For me, a bit of drag is not ok, it means the set failed, at least to a degree, and it may or may not be fixed, either by us or by the anchor itself.

Bruce, I was thinking of the guys who sometimes anchor in over 50' or even 100' of water. Clearly there you have quite a bit of leeway before you would be hitting 'the edges' so to speak, so if you had the zone alarm set on the GPS, and the weather was not nasty, it would be a doddle. If nasty weather, then no way would I consider water that deep an anchorage really. But that's just me.

In really deep water with near 50% chain and 50% line the scope can be greatly reduced.

150 ft of water , 200ft of chain and 250 of line works fine.

Most folks don't carry over 200 ft of chain as the weight gets substantial.

Peter,
Peter you really don't understand that in the PNW coast anchoring in 50 - 75' of water at 4-1 scope your boat hull may be on the beach. You wrote "then the bottom is far from your keel, so if you did drag a bit..so what?" .... So you would likely be crunching your hull on the beach.

How you respond to this gives me a bit of an idea about what it must be like to anchor in your world. And I now understand much more clearly why people think my anchoring at 3-1 is nuts.

And whoever said catenary in deep water and short scope got better .... no .... think about it ... if the anchor rode was vertical there would be no cat at all.

Eric brings up a good point. In this area---- particularly on up the coast in northern BC and SE Alaska-- the water depths can be fairly extreme because of the way the coast was formed or influenced by glaciers and whatnot. So it's not uncommon to find anchorages where the water is south of 100' deep and heading down fast just a few boat lengths from shore. While we have never ourselves anchored in these kinds of situations I'm sure Eric has, thus his desire for an effective anchor in short-scope conditions. I expect he'll find that's not such a requirement down here.

It's my understanding that there are some proven ways of dealing with this. One, which seems to be the most common, is to anchor the boat with the bow away from the shoreline in the shallowest water possible (allowing for the very high tidal range in this region) and secure the stern to the shore. This prevents the boat from swinging in the wind or current and pulling on the anchor from deeper water which could easily unset it.

But even doing this could mean an anchoring depth of 60, 70, 100, etc. feet.

Farther south, in Puget Sound, San Juan and Gulf Islands, and even Desolation Sound most anchorages are not that "radical." We have always been able to find "normal" anchorages where it's possible to anchor in 30-40 feet of water with plenty of swinging room for us and the other boats that were there.

I've posted this shot before from the Desolation Sound area and I suspect similar conditions can be found around the south island in New Zealand, but at the location where I took this photo the water depth in this fairly narrow passage was about 1,000.

The second photo shows the deepwater anchoring technique I described only in this location there are four mooring buoys anchored out in the deep water so you don't have to mess with getting an anchor down in the right place. You can see the stern lines running to shore from our and our friend's boats.

PS--- I should also add that this technique is also widely used here in small anchorages where stern tying is the only way to fit more than one or two boats into the anchorage. This is actually the real reason for the setup in my second shot. The water in the little cove, while deep, is not that deep.

Marin said:

Eric brings up a good point. In this area---- particularly on up the coast in northern BC and SE Alaska-- the water depths can be fairly extreme because of the way the coast was formed or influenced by glaciers and whatnot. So it's not uncommon to find anchorages where the water is south of 100' deep and heading down fast just a few boat lengths from shore. While we have never ourselves anchored in these kinds of situations I'm sure Eric has, thus his desire for an effective anchor in short-scope conditions. I expect he'll find that's not such a requirement down here.

It's my understanding that there are some proven ways of dealing with this. One, which seems to be the most common, is to anchor the boat with the bow away from the shoreline in the shallowest water possible (allowing for the very high tidal range in this region) and secure the stern to the shore. This prevents the boat from swinging in the wind or current and pulling on the anchor from deeper water which could easily unset it.

But even doing this could mean an anchoring depth of 60, 70, 100, etc. feet.

Farther south, in Puget Sound, San Juan and Gulf Islands, and even Desolation Sound most anchorages are not that "radical." We have always been able to find "normal" anchorages where it's possible to anchor in 30-40 feet of water with plenty of swinging room for us and the other boats that were there.

I've posted this shot before from the Desolation Sound area and I suspect similar conditions can be found around the south island in New Zealand, but at the location where I took this photo the water depth in this fairly narrow passage was about 1,000.

The second photo shows the deepwater anchoring technique I described only in this location there are four mooring buoys anchored out in the deep water so you don't have to mess with getting an anchor down in the right place. You can see the stern lines running to shore from our and our friend's boat.

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That's the way we anchor in places like Teakerne Arm - drop the hook into deep water, back up to shallow then stern tie. As a rule of thumb, if the upslope is 20 degrees you only need to lay out 1.2 times the depth in rode to where you dropped the hook to achieve 3:1 scope. That is usually just fine, since with the stern tie, the anchor has to drag uphill for you to drag, and there is no swinging. In other words, drop in 100 feet, layout 120 feet and you have 3:1 scope relative to the bottom if the slope is 20 degrees.

Then again, if your stern ties comes loose, you're screwed....

Well said Delfin and Marin,
Since Peters remark I now understand why many others here can't relate to some of the things we do up here. I've never done shore tying. Always seemed like too much trouble w the dinghy.

Been shopping today. Dropped Chris off at the store and I went on to Anacortes to an old marine goods store at the far north end of the main drag. Found the pump I was looking for. The other thing I found gives me the right to be here on the "big is better" thread. Found a 45# Dreadnought anchor. Gave the guy $95 for it so now I'm a member of the bigger is better club. Of course a 45# anchor for a 30' boat is somewhat of a monster but my friend in Alaska has a 65# Forfjord on his 30' Willard. I don't think I'll be in need of more holding power but in anchoring the door is open to strange things happening.

Here is a pic of the 34# Dread and the 45# Dread is just the same. We weighed it in the store to make sure it was a heavier anchor than I already have. The other picture or pictures is of Ed's boat and it shows how he mounts his anchor and I plan to follow suite and have my yard do the FG mod work on the bow to accommodate the newly acquired Dreadnough. I really like his very clean and tidy anchor installation. Next to nothing sticking out to get damaged while hitting a piling or? It looks so much cleaner too and the entire anchor will be below the rail so my view fwd will be even slightly better than it is now.

I've preached about putting the ground tackle weight into the anchor instead of the rode so I'm taking my own advice. I'll be looking for a short piece of heavy chain to help keep the long heavy shank down low but the rest of the rode will be nylon line as it is now. Would like to get a better drum for the capstan.

The new anchor is in good shape but I will take it apart, check things over and have it re-galvanized. A bit different than Ed's boat my bow rail will be open in a bit of a "V" so the shank will be placed in the V slot and the bow roller. The bronze bow chock will be removed on my boat.

Marin said:

.............
PS--- I should also add that this technique is also widely used here in small anchorages where stern tying is the only way to fit more than one or two boats into the anchorage. This is actually the real reason for the setup in my second shot. The water in the little cove, while deep, is not that deep.

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The second one looks like Buchart Gardens.


In Laura cove (Desolation Sound B.C.), we're anchored in 75' of water and ran a 150' line to shore. To run anything more than a 3/1 scope is hard when depth is a major factor.


It's not uncommon to anchor in 75' +. In the pic we're in our old 23' Cuddy and I carried 20' chain and 200' rode. I wish I had the 50' of chain I carry now in our 26' Cruiser.

Quite right, here in Moreton bay the deepest I have anchored is off Tangalooma Resort in 12 ~ metres of water. Usually it is more like 3-4 metres. I have done the really deep with sharply shelving depths in Lake Taupo in NZ, and there we did do the way Delfin & Marin just described with anchor our as far as possible on the down slope of the bottom, and stern in to the beach/bank and a land based tie - hopefully to a stout tree, or around a large boulder. As least best choice one of those screw into the ground types of peg.
So, Eric my man, I can certainly sympathise, and empathise with your need up in Alaska for a short scope capable set-up, but as Marin says, things should be easier where your now. However, I agree with that Dreadnaught thing you have now, you should not drag anywhere...just be careful not to wreck your back old son.

manyboats said:

Dropped Chris off at the store and I went on to Anacortes to an old marine goods store at the far north end of the main drag.

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Next time you're there, make sure you go into the very back and rummage around. They have every piece of inventory they have purchased but not sold for 50 years back there.