Photos of Anchors Setting

[noelex 77]

We arrived at a new anchorage yesterday and this photo was taken just a few hours ago when visibility improved. 5M @ 4:1.

This is another soft substrate anchorage. The bottom is mud with a fine layer of soft sand on top. By Greek standards, the visibility in this Saronic region is poor, no doubt as a direct result of these softer substrates. I could not see the bottom in 5m of water when I dropped. Yuk.

Anyway, we had no wind overnight and on her pre-breakfast swim my Mermaid managed to take these images before any wave action had stirred up the soft bottom.

It was actually a terrible drop. You would think after nearly nine years full time at anchor we could get it right, but the windlass clutch was looser than I expected and the anchor was accidentally dropped while we were still going forward.

It has not phased the Mantus, which as usual has set in less than a shank length, although if you look closely the drop mark is off to the side so the anchor must have landed backwards and spun around before setting.

The bury is deeper than in other areas where there has been a hard sand bottom. Despite the large fluke area of this anchor, there would be nothing to see if there was no roll bar and float. This is simply a result of the softer substrate and once again I would point out that this is close to the optimum substrate.

Curiously at our last anchorage (with a similar substrate) a boat with a Kobra managed to slowly drag in only 20-25 knots of wind .

Unfortunately I did not see the Kobra underwater. I doubt I would have found it in the murk. I did see the drop which was fine with adequate scope etc although the anchor looked small for the boat size.

[noelex 77]

Our latest anchorage.

We have tried to escape to one of the more remote, out of the way anchorages in search of clearer water. Google earth is a great resource.

We have been partially successful. This anchorage has about 7 to 8m visibility, only about half what we usually find, but a vast improvement from the mud anchorages of late. The substrate is softish gravelly sand. Not as easy for an anchor to penetrate as the softer mud in the last couple of spots, but this is still an easy bottom compared to the hard and difficult sand we are used too. This coarse, reasonably soft sand is similar to the substrate I have often seen in coral areas.

You can see the Mantus has set very nicely. With the softer sand the bury is deeper than we normally see with the more typical hard sand substrates that have featured in many of the photos previously. There is nothing of the anchor visible other than the rollbar and float.

We set the anchor in 5m at 4:1 but when snorkelling we discovered some shallow rocks close to the swing circle so after setting we reduced the scope to a little less than 3:1.

The Mantus has great short scope performance and combined with an oversized anchor I don't have any concerns using a short scope in moderate winds, even in shallowish water

If you need to use a short scope, then setting the anchor initially at a longer scope if possible can be an effective way ensuring the anchor is buried as much as possible.

Subsequently shortening the scope does reduce the holding power, but initially burying the anchor better at a longer scope reduces the impact.

Given the good short scope performance of the anchor and the soft substrate, If we had known the rocks were present we would just have set at the shorter scope, but the technique of setting the anchor and then shortening scope is worth knowing about.







This shows the detail of the gravelly sand. Very different from the mud of our last anchorage, but still a softish substrate when compared to hard sand often found in the more remote Greek anchorages:

[redsky49]

Does that material provide good holding?

[noelex 77]

Yes, the softish sand in this anchorage is close to ideal. The so called "Goldilocks substrate". The sand is soft enough so that even anchors without clever geometry and high effective tip weight can still dig in and set well. On the other hand, the substrate is firm enough that even those anchors without much surface area or those that have a low drag surface geometry still have enough resistance that they are not slowly pulled backwards.

The hard sand anchorages I have shown in a lot of the previous photos are much more of a challenge, being too firm to be ideal. This sort of firm sand can provide excellent holding if the anchor can penetrate, but as you have seen from the photos many anchor designs are not up to this task. They can only dig into the softer surface sand and cannot bury into the firmer subsurface sand.

I also think the ability of an anchor to penetrate a hard sand layer correlates well with its ability to penetrate weed. Weed is a very difficult substrate to test anchor designs. Hard sand provides a much more consistent substrate, but the challenge of cutting through the tough weed roots is similar to the difficulty an anchor faces burying into hard sand.

This softish sand or firmish mud does not show much about anchor performance. Most anchors do well.

[Don C L]

Sorry if I missed it, but how do you run the trip line on the Mantus? From the hole in the shank under or above the arch? BTW what is that arch called?

[noelex 77]

The arch is called a roll bar.

The underwater float is attached to the roll bar. It is primarily there to make the anchor easier to find, especially in thick weed or soft substrate when the roll bar can get completely buried.

[Don C L]

Originally Posted by noelex 77

The arch is called a roll bar.

The underwater float is attached to the roll bar. It is primarily there to make the anchor easier to find, especially in thick weed or soft substrate when the roll bar can get completely buried.

Roll bar! of course. Sorry for my ignorance there, wasn't paying attention. But maybe I missed it, do you have a shot of a Mantus with a trip line attached to the hole in the shank to pull out the anchor backwards if it gets stuck on a rock or coral head? The hole seems high on the shank, I would have thought it would be more effective down closer to the fluke, but maybe I am missing something. In any case to me it appears that it is best to run the trip line back under the roll bar but the only shot I have seen comes from an ad for a trip line product:

[noelex 77]

Originally Posted by Don C L

The hole seems high on the shank, I would have thought it would be more effective down closer to the fluke, but maybe I am missing something. In any case to me it appears that it is best to run the trip line back under the roll bar but the only shot I have seen comes from an ad for a trip line product:

I think the hole the Rocna has at the back of the fluke is the ideal location for a trip line, although it means you also need to drag this rope under the seabed if the anchor sets deeply.

Unfortunately the Mantus does not have a similar attachment point. Attaching the trip line to the rollbar is not as good but it should work OK although I have not tried it.

If you have an anchor that sets quickly the chances of catching the anchor is small and is not something I would worry about unduly. Most cases of the anchor catching something are caused by the anchor taking a long time to set, or when the anchor drags.

Unfortunately, an anchor that sets quickly does not prevent the chain wrapping around an obstruction or a rock. With a good anchor this is far bigger problem. A trip line does not help if the chain is caught, although occasionally there is enough free chain between the obstruction and the anchor that the anchor can be raised to the surface using a trip line. Even though the chain is still caught it gives you more options. At the very least you can unshackle and therefore save the anchor.

[Steadman Uhlich]

NOELEX,
A suggestion: Given the higher cost of the larger new generation anchors, and interest in retrieving stuck anchors via a trip line or other techniques, I think that would be a good new topic on the forum, one hopefully covered with video and photos and clear narration, and use of different commercial gizmos and DIY tools and techniques.

[Don C L]

Originally Posted by Steady Hand

NOELEX,
A suggestion: Given the higher cost of the larger new generation anchors, and interest in retrieving stuck anchors via a trip line or other techniques, I think that would be a good new topic on the forum, one hopefully covered with video and photos and clear narration, and use of different commercial gizmos and DIY tools and techniques.

Good idea, and it's not just the cost of buying an anchor. Once you're there, the cost of losing an anchor, and a lot of rode too, is far more than the actual $ cost. A thread called "photos of anchors being retrieved!" except that it will probably be full of murky, dark photos in colder water with vague images of tree trunks and old cars instead of those beautiful waters of the Med!

[jongleur]

I can only find one review for the
AnchorWitch and a couple of videos.
Does anybody know how to contact
AnchorWitch? Is it still available?
Count me impressed.

[noelex 77]

Thanks for the suggestion Steady, but I think I will have to leave that as a project for someone else. I am finding it hard enough to keep up with the anchor photos .

I hope to keep this series as a means of documenting how boats are anchoring in the real world. If an anchor gets stuck don't worry I would be the first to swim over to help (with my camera as well of course so there will be lots of photos).

When buying a new, expensive anchor people naturally worry about the risk of the anchor getting caught. Ironically, most of the new generation anchors set very rapidly and rarely drag so the risk is much smaller than with their old anchor.

It is still kind of weird when you first drop what might be a $1000 worth of anchor for a large boat into the murk so I can understand the interest in trip lines.

Originally Posted by Don C L

A thread called "photos of anchors being retrieved!" except that it will probably be full of murky, dark photos in colder water with vague images of tree trunks and old cars instead of those beautiful waters of the Med!

[noelex 77]

A private steel yacht dropped this Delta.

They seemed to give the anchor a decent amount of setting force and I hoped in this slightly softer sand to get some photos of a Delta setting deeper.

Sadly the Delta has done a typical Delta set. Perhaps the setting force was not as much as it looked, but I suspect the shortish scope was most of the problem. Deltas don't do well on shortish scopes. This was 4:1 in 4m.

[noelex 77]

A new anchorage.

Unfortunately, the forecast was incorrect. When we arrived the wind was 180° off the predicted direction. This also meant we were on a lee shore with a rather unforgiving looking rocky shoreline.

It is times like this you need a big new generation anchor.

This was the set. We used our normal setting procedure of full reverse for 30 seconds, but the setting force was a little higher than usual, as there was some wave action from the onshore wind.

Even small waves create considerably higher loads on the anchor.

The wind swung around the next morning, but this photo was before the change.

[noelex 77]

This was a Kobra dropped by a private boat. I have generally found the Kobra to be a slightly better anchor than the Delta. The Kobra is a convex plow anchor with a similar blade shape and overall design to the Delta so underwater, as you would expect, they share a lot of very similar characteristics. In my opinion the Kobra is usually just slightly better. My guess is the lighter shank of the Kobra combined with the slightly more tapered blade gives it an edge over its surprisingly more popular, and more expensive, rival from Lewmar.

Anyway, the Kobra on this occasion does not support those accolades. It has given what is a very typical "Delta like" result. There is a long setting mark, terminating with a barely adequate result. If you look at the long drag mark, what is even more disappointing is that it set better initially and then the anchor gives a skip and the setting mark becomes shallower.

Once again the scope may have been a factor. It was 3:1 in 6m. While this should be enough for a reasonable set, the convex plow anchors are a little fussy about scope. I suspect a bit more chain would have given a noticeably better result.

Note: we were in the water nearby when the boat dropped. As some of the photos were taken just after the set there is some stirred up sand.