Which type anchor?

[SteveK]

I have had poor results in sloppy mud with a standard danforth and plow anchors, but a Fortress in the "mud" position grabbed instantly and held like a bulldog. Shovel like the SuperMax aso do well.

The fortress is a danforth clone, is it not. Longer in shank and lighter.
What makes it hold mud better?

 

[rslifkin]

The fortress is a danforth clone, is it not. Longer in shank and lighter.
What makes it hold mud better?

It can be opened up to a wider fluke angle for better bite in very soft mud.

 

[HopCar]

The fortress is a danforth clone, is it not. Longer in shank and lighter.
What makes it hold mud better?

You can adjust the angle of the blades for mud. The traditional Danforth is designed for sand.

 

[Nomad Willy]

The fortress is a danforth clone, is it not. Longer in shank and lighter.
What makes it hold mud better?

There is more to it than the throat angle adjustment.
Just look at the shank. WAY different.
The Fortress was clearly inspired by the Danforth but also clearly there was no attempt to “duplicate” the Danforth.
There are plenty of Danforth clones and quite a few “better mousedtraps” too.
So no it’s not a clone but Fortress could easily fit the better mouse trap configuration.

 

[ranger58sb]

It can be opened up to a wider fluke angle for better bite in very soft mud.

You can adjust the angle of the blades for mud. The traditional Danforth is designed for sand.

There is more to it than the throat angle adjustment.
Just look at the shank. WAY different.

The Fortress also has an attachment called "mud palms" to help direct the flukes downward while setting. Fortress recommends always using the mud palms, even when not in soft mud.

-Chris

 

[rslifkin]

The Fortress also has an attachment called "mud palms" to help direct the flukes downward while setting. Fortress recommends always using the mud palms, even when not in soft mud.

-Chris

Good point. Most Danforths I've seen have something similar, but the Fortress ones are a bit more aggressive. Basically, it's a lightweight, upgraded Danforth.

 

[O C Diver]

I use a Rocna on all types of bottom, never been disappointed. Use atleast 7:1 scope, more when the wind is forecast to pickup. I sleep well at night on the hook.

Ted

 

[Nomad Willy]

The Fortress also has an attachment called "mud palms" to help direct the flukes downward while setting. Fortress recommends always using the mud palms, even when not in soft mud.

-Chris

The Danforth type requires the palms because there would be almost no angle of attack w/o them. The flukes would otherwise just slide over the bottom w/o catching enough bottom strata to “hook up”. Even an airplane wing needs some angle of attack to create lift.

Many other anchors have the equivalent of the Danforth palms to turn the fluke tips downward to get a grip on the bottom. Dreadnoughts, Navy and other stockless types have a bit of a flange at right angles to the flukes that turn the fluke tips downward into the seafloor. Same function. Slightly different configuration.
While walking the docks I’ve seen danforth type anchors that have steeper more aggressive palms that stick up higher or/and have a steeper angle of attack. Some are bent a bit at the trailing edge like airplane flaps.
Yes the palms are an essential part of the design.

The Dreadnought in pic #1 has a big "ear" that sticks up (and down) to jack up the back of the anchor to force the fluke tip down into the seafloor.
The Navy anchor in pic #2 has two sets of ears (greater stability) that accomplish the same thing.
Pic #3 is a next-gen anchor that has the equivalent of the ears on the stockless anchors above. The outboard corners of the TE of the single fluke are bent down enough to lift the TE and use the resulting small degree of angle of attack increase to direct the fluke tip to dig in.
So the palms are used in several ways to jack up the back of the fluke or flukes to achieve the desired angle of attack.

 

[Art]

I use a Rocna on all types of bottom, never been disappointed. Use atleast 7:1 scope, more when the wind is forecast to pickup. I sleep well at night on the hook.

Ted

Rode length to attain 7:1 [or even more scope] is great if you have "swing" room and ample rode for getting to that anchoring scope. However, for several reasons, not all anchoring locations offer that "swing" room opportunity.

On another front regarding "scope": Not all boats carry enough rode to reach 7:1 scope... unless anchoring in relatively shallow waters.

15' water depth = 105' rode
30' water depth = 210' rode
50' water depth = 350' rode

That said... most anchoring locations have relatively shallow depths, so the longer length of available rode is not too often an issue. But, the 7:1 scope "swing" room can be an issue.

I often anchor in 20' +/- depth; requiring 140' rode. Having 250' of rode makes it easy to attain 7:1 scope. What works well for us in this case is that the anchor mentioned here is a rear anchor and there is no need for "swing" room. The location of which and the manner in which we secure boat's bow is unusual; front anchor scope does not come into play.

PS: Rear anchor mentioned above is a Fortress, set up in its best mud-hold configuration. Works great!

 

[Alaskan Sea-Duction]

I use a Rocna on all types of bottom, never been disappointed. Use atleast 7:1 scope, more when the wind is forecast to pickup. I sleep well at night on the hook.

Ted

Although I normally have a scope of 3:1 or 5:1.

 

[Simi 60]

I will link you to this blog that does a decent job on explaining the various types, their strengths and weaknesses. Generally get a "modern" anchor for your primary and get a fluke type (like a Danforth or Fortress) for you secondary.

https://www.anchoring.com/blogs/anc...guide-how-to-choose-the-best-boat-anchor-type

Failed miserably in this description.
I didn't bother reading others

Plow Anchor with Roll Bar
Rocna

There are several anchors on the market today that are essentially plow anchors with roll bars. These include the Rocna, Manson Supreme, and Bugel.

Each of these anchors are essentially a variation on a plow style anchor

 

[rsn48]

Thought I would throw this out there for those who visit Victoria BC. Very close to the Empress Hotel is the Maritime museum. They have a display which is basically a box of dirt and miniature anchors you can drag through the dirt.

Here is the Museum's blurb on it:

ANCHORS AWAY!
Did you know anchors are not meant to act like grappling hooks, but instead are meant to dig into the seafloor and work together with the weight of the rope or chain to keep the boat in place? Drop anchor yourself with our interactive Anchors Away display, featuring anchors from different historical periods.

 

[O C Diver]

Rode length to attain 7:1 [or even more scope] is great if you have "swing" room and ample rode for getting to that anchoring scope. However, for several reasons, not all anchoring locations offer that "swing" room opportunity.

On another front regarding "scope": Not all boats carry enough rode to reach 7:1 scope... unless anchoring in relatively shallow waters.

15' water depth = 105' rode
30' water depth = 210' rode
50' water depth = 350' rode

That said... most anchoring locations have relatively shallow depths, so the longer length of available rode is not too often an issue. But, the 7:1 scope "swing" room can be an issue.

I often anchor in 20' +/- depth; requiring 140' rode. Having 250' of rode makes it easy to attain 7:1 scope. What works well for us in this case is that the anchor mentioned here is a rear anchor and there is no need for "swing" room. The location of which and the manner in which we secure boat's bow is unusual; front anchor scope does not come into play.

PS: Rear anchor mentioned above is a Fortress, set up in its best mud-hold configuration. Works great!

Depth of water is a key factor in scope ratio. As I mostly anchor between 10 and 20' a difference between 5:1 and 7:1 is only 40'. I think it's reasonable to adjust scope relative to water depth. I have no experience anchoring in >50' of water, but couldn't imagine being comfortable with 50' of chain in 10' of water.

Regarding swing room and rode, I carry 350' and use whatever percentage I feel necessary. I anchor for my own safety and comfort level. If someone coming in after me doesn't have enough swing room, they need to change where they're anchoring. If I don't have enough swing room when anchoring, I will move.

Ted

 

[HopCar]

Depth of water is a key factor in scope ratio. As I mostly anchor between 10 and 20' a difference between 5:1 and 7:1 is only 40'. I think it's reasonable to adjust scope relative to water depth. I have no experience anchoring in >50' of water, but couldn't imagine being comfortable with 50' of chain in 10' of water.

Regarding swing room and rode, I carry 350' and use whatever percentage I feel necessary. I anchor for my own safety and comfort level. If someone coming in after me doesn't have enough swing room, they need to change where they're anchoring. If I don't have enough swing room when anchoring, I will move.

Ted

Going from 5:1 to 7:1 only makes a 3 degree difference on the angle of the rode. Compass Marine published an interesting test on this subject. Going beyond 7:1 is pretty pointless.
https://pbase.com/mainecruising/anchor_scope&page=1

 

[Simi 60]

Its why I like using poly rope instead of chain counter.
If I have less than 10 ft under the keel it gets let out to first red (25m/80ft)
If there is more than ten but less than 20 out to the 2nd red (50m/160ft)
And so on until I get to 3 - I can count that far.

If things are looking real bad weather wise it pretty much all goes out.
Chain doesn't work sitting in a locker.

 

[Slowmo]

For years I used a modified Danforth (more fluke angle and bars across the pivot to prevent the rode from tripping the anchor). It worked very well in the mud and sand of the PNW. I'm now using a 22kg Bruce on a 40' boat. I was dubious at first, the Bruce was smaller than my old Danforth type on a boat with more windage. But to my surprise it has worked very well including some unfavorable conditions. This included a blow while stern tied that put a huge load on it, but it held just fine (wasn't so easy to retrieve it the next morning...).

Anyway, I think if you use good anchoring techniques many anchors can work well.

 

[Nomad Willy]

I agree w you Slomo,
Are you using a genuine Bruce anchor?
One nice thing about the Claw is that if you buy one at least a size up it can be a universal anchor. OK to good in mud, rocks, sand, gravel most all other bottoms. And it fits on the bow roller better than any other.

I have some theories about Claw anchors that generally revolves around thinking that small differences in shape can make big differences in performance.
The biggest difference in the Claws that I’ve noticed is that the Bruce anchor has much less throat angle. Lewmar Claws have much more.
Have you had any similar thoughts or made other observations re differences?

 

[O C Diver]

Going from 5:1 to 7:1 only makes a 3 degree difference on the angle of the rode. Compass Marine published an interesting test on this subject. Going beyond 7:1 is pretty pointless.
https://pbase.com/mainecruising/anchor_scope&page=1

Parks, with all do respect, it's not about the 3 degrees, it's about how much chain lays on the bottom and how shock load reaches the anchor. With all chain, it's rare for the rode to be straight, as the weight makes it curve. In moderate winds, with extremely shallow water and modest scope, the chain may straighten out, more of the shock load reaches the anchor and may lift the shank. I suppose that Compass Marine may be basing their information on a combination rode where more of the shock is absorbed by the stretch of the nylon.

Doubt there's an anchor manufacturer that doesn't endorse the value of some chain and the shank lying on the bottom.

As for value above 7:1, couple of years ago I was anchored in Mile Hammock off Camp Lejeun, NC. With 40+ knot winds, I dropped the hook in 10' of water with 100' of chain to the snubber and slept soundly. Could have been ok with 70'; some guy with a sailboat and a CQR might have tried 50'. Reality was that I knew the chain at the anchor was in the mud and the anchor wasn't coming out.

Ted

 

[HopCar]

Ted, I think he was just pointing out that at between 5:1 and 7:1 the pull is almost horizontal without taking into account the catenary. Add chain to the equation and I bet it gets horizontal at even less than 5:1. It certainly doesn’t hurt to put out more I usually did.

 

[Spinner]

Oh well, here’s another opinion! Nice big Spade anchor, 300 feet of all chain rode. I cruised the northern BC coast last summer, often in 60-100 foot deep anchorages. Those depths, coupled with large (15 ft+) tidal swings, don’t permit a nice 7:1 scope. I think the best I put out was about 4:1.

No problems, even when an unexpected wind blew up in Prideaux Haven (Desolation Sound). Lots of boats around me dragged anchor, but my boat didn’t move

With the big tidal swings, bow about 8 feet from the water, and often little swing room, I don’t see putting 700 feet of chain in the locker to achieve that kind of scope.

Although, if I did add another 400 feet of chain, I might splice it with a short length of suitable nylon line. The nylon would give me a place to cut the rode if needed, and I would still have ample chain for my second primary anchor. Does anyone ever do that??

 

[FF]

"I have 5’ of chain (oversized) and haven’t dragged. I think chain is mostly to help an anchor set."

Yes , using this concept there is no reason to purchase a windlass that can accept heavy chain.

If there is enough deck space between the anchor shank and windlass5 or 6 ft of 1/2 inch chain can be used.

Since its never stored below , it need not be scrubbed of mud stink.

We figure 8 the anchor line on deck during a cruise , so it is instantly ready to deploy , no wondering about hockels coming up from a small hole under the windlass.

 

[rslifkin]

For the how much chain questions:

My old setup was a 6' leader of 1/2" chain, as my original windlass was line only. Never had an issue with jams coming out of the locker though, even though it was pulling 5/8" 3 strand through a 1" pipe from the locker. That setup will become a spare rode, as it's reasonable to manage by hand.

With the new setup, I'm going for a longer length of lighter chain to reduce bottom chafe concerns without adding excessive weight. The new windlass handles chain and line spliced together on the gypsy, so there's no handling issue with the combo. But for my cruising grounds and the nature of my boat, I see no reason to go for all chain.

As far as mud stink, being that I'll have chain below decks now, I'm adding a washdown setup so I can spray the gunk off the chain as it comes up. The anchor locker floor is being re-done with a 1" drain overboard as well to allow the locker and contents to be rinsed out easily if needed.

For Spinner's idea of having 300 feet of chain and possibly wanting more, at that length I'd back it up with a good length of decent size nylon. 300 feet of chain is enough that I think carrying more would very rarely provide a benefit even if more total rode length is useful.

 

[Slowmo]

Yes, Mine is a Bruce brand anchor, not a generic. Though Bruce no longer is in the anchor business, I think Lewmar took over production?

 

[Nomad Willy]

Lewmar and many others too. Probably 7-8. And they are all different.
Many skippers here tell how great their Claw is and others complain of dragging.

Re the mud anchor for our OP two things come to mind.

1. Perhaps the best mud anchor is the anchor that dosn’t plug itself w mud or otherwise get so much stuck on the anchor that no longer performs as an anchor. In that condition a boat will drag w/o much wind present.
The ARA (Anchor Right Australia) anchors are designed to shed mud readily enough so they continue to perform well as anchors. Also they set and re-set unhindered w mud that causes other anchors to cease to perform as anchors. See Anchor Setting Video’s. The supremely dependable anchor.
The SARCA also has a retrieval slot in the shank that allows you to retrieve your anchor pulling it out backwards. For years I didn’t pay much attention to this feature but now I really like it. PNW waters have many spots that were big logging shows in the old days and getting an anchor stuck there is likely. I never have but while anchoring in these known places I frequently used the anchor I’d use the anchor I’d most likely not suffer from loosing. Frequently that would be my lowest performing anchor. But now w the SARCA I can anchor anywhere and know I’m probably going to get my anchor back in the morning.

2. I have an anchor test in my computer that out of 18 anchors the Spade was a top performer. The Spade was (most believe) the original “next-gen” anchor and also the original scoop anchor design. The scoop anchor now is the most popular type of anchor sold. But it’s holding power, it’s reversal performance and general dependability. The Spade’s performance, construction and timeless (for anchors) design makes it a top choice. I think I can say it’s been a top performer in all the anchor tests I’ve seen. Not perfect though as it is heavy and expensive.

Here is a picture of a Spade that shows the ballast chamber that is rarely seen.

 

[rsn48]

Here is another reference, note it is put out by Rocna but it includes a number of "studies."

https://www.petersmith.net.nz/boat-anchors/independent-performance-testing.php

 

[Nomad Willy]

Thanks rsn48 but I don’t consider much put out by Peter Smith as being objective. There are numerous tests that show the Rocna doing poorly.

No disrespect to the product other than the mild steel shanks but that should have put Rocna out of the business forever IMO.
But the anchor seems good (or better) except for very slimy mud and very short scope performance. Look at all the anchors that do much better. I wouldn’t be too concerned about the Rocna’s mud holding problem unless it has mud compacting issues but even if the Rocna was manufactured by a more respectable manufacturer I’d pass on the short scope limitation. Why buy a Rocna when there are plenty of comparable anchors.

 

[Shrew]

15' water depth = 105' rode
30' water depth = 210' rode
50' water depth = 350' rode

These number don't account for the height of the attachment point on the bow to the water. If you also have a 6 ft high bow pulpit or cleats, then the actual number for 7:1:

(15+6) x 7 = 147
(30+6) x 7 = 252
(50+6) x 7 = 392

Although I normally have a scope of 3:1 or 5:1.

We also anchor at around 3:1 and pay out to 5:1 in a blow. However, we calculate for bow height and depth of transducer. I suspect most people who think they are 7:1 are actually much less.

 

[Mako]

"I have 5’ of chain (oversized) and haven’t dragged. I think chain is mostly to help an anchor set."

Yes, using this concept there is no reason to purchase a windlass that can accept heavy chain.

I followed suit similarly with my small boat, anchoring extensively. It was a 20ft panga, only a couple thousand pounds loaded. 22lb Danforth copy with 3ft of thick chain (I recall 3/8", not certain though) and then rope rode.

The bottom had serious limestone formations and after 6 months the rode/chain splice would show wear, which I would cut off and redo. The anchor held in winds up to about 30 knots, but sometimes wouldn't penetrate the hardpan bottom until I ground the leading edges sharp.

Anyway, I really liked this concept. If I were outfitting a future boat with a rope rode, then I would prefer to have a super-heavy anchor with a short 6ft leader of heavy stud link, rather than the typical-sized anchor with one boat length of typical-sized chain.

 

[Nomad Willy]

Mako,
I’m still anchoring w 4’ of 3/8” chain then 5/8ths brait. No problems.
That tells me the chain is mostly for setting and keeping the shank end down on the seafloor .. to insure proper setting position and angle of attack of the fluke.
Don’t anchor much anymore though.

Shrew,
I agree. Many think they are anchoring at 4-5/1 but when the tide moves one tends to forget bow height and transducer position. So 3-1 is probably the norm for most.

Rango wrote;
“Shovel like the SuperMax aso do well.”
And they usually stay buried when veering. Not depending on a reset is a good thing.

 

[O C Diver]

These number don't account for the height of the attachment point on the bow to the water. If you also have a 6 ft high bow pulpit or cleats, then the actual number for 7:1:

(15+6) x 7 = 147
(30+6) x 7 = 252
(50+6) x 7 = 392



We also anchor at around 3:1 and pay out to 5:1 in a blow. However, we calculate for bow height and depth of transducer. I suspect most people who think they are 7:1 are actually much less.

This is a common assumption mistake that really only applies to combination rodes. As I indicated in my post, with my all chain rode, the calculation is based to the surface of the water as a snubber is always used. Between the snubber length, attachment point, and amount of additional chain spooled out between the snubber hook and the bow roller, the anchor rode often resembles an angle with the snubber hook in the apex.

It has also become much more common to see a permanent bow eye installed slightly above water level, to which the snubber is attached. This obviously eliminates the need for any above water scope calculation. It also provides a nicer ride at anchor in seas, I'm told.

While some may not feel it worth the effort, I set one depth sounder to read actual water depth and another to read depth below the skeg (clearance depth). This is quite easy to do with the transducer offset adjustment, and gives depth readings that are useful instead of approximations.

Ted