Photos of Anchors Setting

[noelex 77]

Originally Posted by BigBeakie

Your last photo in the harder bottom substrate made me wonder re the bigger is better question. In that bottom, where there is not as much penetration, do you believe that if you had high winds, ie. significantly above 30 kts, that the bigger anchor would just dig in more with the additional force? Or would it be at risk of releasing and then dragging?

Providing it is just a hard substrate and not rock, the anchor will just dig in more and more with higher wind. In fact, these hard substrates give excellent holding providing the anchor can penetrate. Many designs cannot and just skid along the surface.

The biggest difficulty is with the initial penetration. Once the anchor has achieved this, as the Mantus has done, it will invariably just continue to set deeper with more force.

There are a couple of concerns with this sort of substrate:

1. The appearance could be caused by rock.
Sometimes it is just an isolated buried rock beneath the surface, sometimes it is a layer of rock. My setting force is the equivalent of about 25-30 knots average wind. In winds higher than this the anchor needs to penetrate more to provide enough grip. In a simple hard bottom this will happen. With rock under the sand it cannot.

2. Rotating around to new wind direction.
If the set is less deep than shown there is a risk with a change in wind direction the anchor will break out. I have seen my Rocna shuffle on several occasions with a shallower set caused by hard sand and it still manages OK, and I would expect the Mantus to perform fine with this amount of set (the Mantus actually rotates a fraction better than the Rocna), but there is a certain minimum amount of bury where a "shuffle" becomes less likely.

A smaller anchor has less holding power, but it will set deeper for the same amount of force. Thus if a minimum amount of bury is not achieved in a very hard substrate it is conceivable a smaller anchor may have "shuffled" better and be a superior choice in conditions of changing wind. However, the only time I have achieved a set shallow enough to cause concern with either of my two oversized anchors, has been in conditions where there has been rock under the substrate and in these conditions a smaller anchor will not penetrate deeper and the greater fluke area of a larger anchor gives more security.

[downunder]

Originally Posted by BigBeakie

Noelex,

Compliments to the mermaid on these photos, they are excellent.

Your last photo in the harder bottom substrate made me wonder re the bigger is better question. In that bottom, where there is not as much penetration, do you believe that if you had high winds, ie. significantly above 30 kts, that the bigger anchor would just dig in more with the additional force? Or would it be at risk of releasing and then dragging?

I realise that is what we would all want to know , but what is your opinion on what would happen in that photo if we could video it and apply much greater force, such as 50 kts wind on a high windage cat?

BB,

Get some feedback when you sail Keshi from the owner re his Excels burying.

For me on a cruising vessel bigger is better whatever the anchor.

cheers

[NornaBiron]

Originally Posted by Ann T. Cate

I sure wish some of the Aussies would post more pictures: different anchors, different bottoms, plus it's summer here.

We're now in the Red Sea with 9 other boats and are hoping to continue posting anchor pics. I think that we'll be picking up buoys in most anchorages though.

[noelex 77]

This is just a shot from the surface, but the wind has swung about 120 degrees. It is not strong, at 25 knots or so, but very gusty and constantly changing direction. Not conditions anchors like.

The Mantus has so far rotated about 40 degrees. Other than the rotation it looks virtually identical. It has not moved backwards and remained quite level despite the chain pull at 45 degrees. It shows every sign of "shuffling" successfully at this early stage despite the shallow set in hard sand.

[Prairie Chicken]

No Ken, I caught the bug from Noelex & his Mermaid. I'm very envious of their u/w camera. For the time being I'm limited to surface shots with my Nikon.

I think Noelex's posts & others are doing a great job to enlighten our understanding of the science of anchoring. I only wish I could contribute more of my own to the collection.

[BigBeakie]

Thanks Noelex. The definitive anchor test would be to underwater video how anchors set, and then all manner of scenarios could be tested. It would be a massive job trying to undertake several anchor type comparisons on different bottom types such as this hard sand, but it certainly would be fascinating.

Downunder, I did speak to Greg about the various conditions he anchored in with the Excel and he is really delighted with it's performance under everything he has encountered, including some fairly serious winds and poor holding. So the Excel is on my (very) short list for the cat.

[jcapo]

Originally Posted by noelex 77

Frankly this anchor is too good to return though, so I have paid full retail price (less the standard CF discount) for the anchor.

How doe one get the "standard CF discount"?

[noelex 77]

Originally Posted by jcapo

How doe one get the "standard CF discount"?

Hi Jcapo

You need to watch the monthly giveaways on Cruising Forum .

SaucySailoress does a fantastic job organising these. In the September monthly giveaway, as well as the prizes there was an offer for everyone that entered to receive a 10% discount and free shipping.

The link is here:

http://www.cruisersforum.com/forums/...in-132016.html

[noelex 77]

My Mermaid braved the cold for some better photos.

The wind has been flipping back and forth from several directions. I suspect the anchor has shuffled around a fair bit, although in light wind just the chain will move, leaving the anchor in the same location.

Here it is about 50 degrees from its original location and it looks unchanged apart from the rotation.

[Wotname]

Originally Posted by noelex 77

My Mermaid braved the cold for some better photos.

The wind has been flipping back and forth from several directions. I suspect the anchor has shuffled around a fair bit, although in light wind just the chain will move, leaving the anchor in the same location.

Here it is about 50 degrees from its original location and it looks unchanged apart from the rotation.

Well done Mermaid

It's hard to get use low quality again when we have had high quality for such awhile - I'm talking about images

Keep on being brave during the winter months; there's always a hot coffee and a SM as a reward.

[noelex 77]

Another anchorage and another great set from the Mantus. The wind was none existent when we dropped. You can see the effect of our prop walk swinging the boat to port and therefore the shank towards the camera during the setting procedure. This curved setting direction, spanning about 25 degrees, is not ideal, but it has had very little effect on the Mantus with only a very slight list.

If there is anything more than a light wind the boat tends to stay the directly downwind despite the prop walk and you get a slightly better set from the constant direction of pull.

It is worthwhile, when there is some wind, trying to set directly downwind, especially with an anchor that is not as roll stable as the Mantus. The same with current.

Keeping the pull in the same direction while the anchor is setting is better, where possible.


6m @4:1.

[noelex 77]

Mantus digs up an amphora.

The wind has been in the high 20s for the last 24 hours. Around 25-30 knots is the stage when the wind force exceeds my setting force and the anchor starts to bury deeper.

There is plenty of room here so I have let some more chain. The scope is now 7:1

The Mantus has rotated around about 30 degrees. It has also settled just a fraction deeper with this wind. To do so, it had to move backwards, although even looking carefully at the photos it is hard to pick any backwards movement at all. The Mantus buries very quickly. However, as you can see, it has unearthed the top of an amphora.

The sand is not very hard here (you can see how rapidly the setting mark is filling in) so possibly as the sand has levelled out the top has been exposed.

Anyway quite a remarkable once in lifetime observation.










This island has a rich history with acres of Hellenistic/Roman ruins. Amphorae were used by ancient Greeks and Romans, with usage stopping around the 7th century AD.

I was amazed this one was not filled with sand. I can only think the Mantus has knocked off the stopper. It may mean it is complete. Unfortunately, they were used to transport olive oil, wine, honey etc rather than gold and coins, so no riches here .

This is a museum photo of a similar amphora with dual bands on the handle:

[SVNeko]

dig it up!

[Wotname]

You must be "a glass half full" kinda guy.

One man's "Anyway quite a remarkable once in lifetime observation." is another man's "inches away from a fouled anchor"

[noelex 77]

Thunderstorms swept through last night bringing 30 odd knots of wind with them. The Mantus has just settled slightly deeper into the sand, but you have to look very carefully to see any change.

Interestingly, three freighters came to shelter along the coast and two of them dragged despite the relatively modest wind.

Underwater visibility has dropped off with the wave action, but here are a couple more photos of the amphora taken by my Mermaid. I am not sure what is inside. It's possibly a couple of shells, so I wonder if an octopus has dug it out, although the lack of growth suggests it has been completely buried.

The other handle is now exposed and the amphora looks intact: