Photos of Anchors Setting

[hoppy]

Originally Posted by hoppy

OMG I think I'm going to die

Thankfully it only took me a couple of minutes to get unstuck.

The mess was perhaps 5-7m down, so I let out some chain and dived down. Luckily I was able to unwrap the chain from the rock on my first attempt. I swam back to the boat as quickly as possible and got to the windlass and bought up the anchor before anything else could happen.


I was lucky that there was not so much wind so I had some slack to play with. If it was much deeper I would have struggled to reach it, but I did have my scuba gear onboard.

I'm not sure how I would have got unstuck if it was deeper and no scuba as I am alone. I guess that to get off without diving, i'd probably need someone on the surface snorkeling giving directions to someone on the bow running the windlass and relaying directions and a hell of a lot of luck

[hoppy]

After the rock incident I went to a safe sandy anchorage

It was blowing 20+ so I decided to not backdown and just see how it goes. During the afternoon the highest gust was 31 and this is the result

[malbert73]

How long is the set mark? I see parallel chain marks- are those from prior anchor position and did it slowly drag? Or someone else's chain marks?


Sent from my iPhone using Cruisers Sailing Forum

[hoppy]

Originally Posted by malbert73

How long is the set mark? I see parallel chain marks- are those from prior anchor position and did it slowly drag? Or someone else's chain marks?


Sent from my iPhone using Cruisers Sailing Forum

I dropped about 5m directly behind a previous set mark.

Wind swung 180 but the chain held us over the anchor

[noelex 77]

This was a CQR copy, sometimes called a Plow anchor in 8m @ 5:1.

In this nice, ideal sand the plow has done one of the best sets I have seen from this type of anchor for a while. It has rotated upright and the fluke is reasonably buried, although you can see even in this soft substrate it has taken a very long setting distance to do this.

It does show that in this close to ideal substrate most designs of anchors can give a good performance. Anchor design makes much less difference in the perfect substrate.

[noelex 77]

This was a fixed convex plow anchor. I saw the drop and think it was a Shark.

In my view, the Shark is not one of the greatest anchors, but in this ideal substrate it is doing very well. The fluke is very nicely buried. There is some heaping up and the setting distance is longer than the best anchors, but in this substrate all anchors are doing well. It is therefore difficult to pick much difference in performance between the best and less effective designs.

It is nice to show the fixed convex plow anchors finally doing well.

[noelex 77]

This Delta was dropped by a large powerboat, but it was only a small anchor. 4m @ 10:1.

It has done a great job in this nice sand. The fluke and even the shank are (just) completely buried. The only slight criticism is that there is a reasonable amount of heaping up, but this is an excellent performance. It is just a pity that in more challenging substrates the anchor performance deteriorates so sharply.

[eheffa]

Thank you Noelex for creating this thread and everyone else who has contributed to make this such a fascinating and informative thread. It's taken me some time to read through the whole 165 pages but I'm very glad I did.

Our boat (a 22 ton Nordic Tug 37 ~40 ft LOA) lives in the heart of the Gulf Islands (and San Juan Islands) with access to several life-times worth of rocky shoreline. We cruise all year round. We anchor a lot with our Rocna 25 Kg anchor. Viewing the anchor on the bottom and diving to see the set is not possible most of the time.

We have had a good number of times where we were unable to get the anchor to set: Heavy eel grass and steeply sided anchorages in what acted and sounded like impenetrable shelving rock. Not having a view of the bottom makes much of this just guess-work. I'm also worried that we could foul the anchor. There many rocks and many of these bays have previously hosted booming-grounds and aquaculture operations.

1. Would having a high resolution 3D side-scanning depth sounder allow for more informed anchor placement. Is anyone out there using that technology as a surrogate Mermaid ?

2. We often anchor in a popular Marine park (Winter Cove on Saturna Island). The bottom is sand / mud/ shell. It sets quickly and well but this bay has a lot of current which changes direction ~ 180 degrees with every tide change. In addition it is subject to modest wind on occasion. We have had a number of nights where things are lumpy and there is a fair bit of confusion with competition between current and wind. Under those conditions we are often awakened by intermittent periods where the anchor chain produces a deep low frequency rolling thunder sound. (We use a symmetric two-line bridle with a chain-hook taking tension off the bow roller.) When we first experienced this I thought we must be dragging but I would get up to see that we have not moved from our "Circle". I have concluded that the chain must be scraping or dragging across rock on the bottom but have no way to verify this. Can anyone here tell me if they experience a similar thing and what they have deduced to be the cause? (We have had this happen in other locations but the Winter Cove location is quite consistent.)

-evan

[Panope]

Evan, I too have had intermittent "growling" of the chain in what I believe to be a plain old sandy/mud bottom. My conclusion is that sometimes the chain is being dragged across a portion of itself or the anchor.

Steve

[noelex 77]

Originally Posted by eheffa

Would having a high resolution 3D side-scanning depth sounder allow for more informed anchor placement. Is anyone out there using that technology as a surrogate Mermaid ?

Thanks for your kind words Evan.

I have a reasonable quality fishfinder on board, and another one in the tender, but with the clear water here I have not paid much attention to the displays. The area I am cruising has a lot of anchorages with smooth rock. It is hard to visually pick the difference between smooth rock and sand from the bow, even in clear water. I have started to pay more attention to my fishfinder.

I even spent several hours in the tender motoring over areas I had snorkelled. I thought it would be easy to reconcile what the fishfinder was displaying with what I knew about the bottom consistency. I came away confused. I hope some more experimentation will help .

The 3D side scanning images look amazing. I have zero experience with these, but you would think it would be much better than a conventional fishfinder and very helpful especially in avoiding rock and debris.

Originally Posted by eheffa

Under those conditions we are often awakened by intermittent periods where the anchor chain produces a deep low frequency rolling thunder sound. (We use a symmetric two-line bridle with a chain-hook taking tension off the bow roller.) When we first experienced this I thought we must be dragging but I would get up to see that we have not moved from our "Circle". I have concluded that the chain must be scraping or dragging across rock

Chain is very good at grumbling along the bottom. The harder the bottom generally the more noise it makes. Usually the snubber eliminates most of this (providing the connection is not on the bottom).

[Don C L]

Originally Posted by eheffa

When we first experienced this I thought we must be dragging but I would get up to see that we have not moved from our "Circle". I have concluded that the chain must be scraping or dragging across rock on the bottom but have no way to verify this. Can anyone here tell me if they experience a similar thing and what they have deduced to be the cause? (We have had this happen in other locations but the Winter Cove location is quite consistent.)

-evan

The Kraken. At least that's what I tell my kids if we hear any unknown sounds! It might seem I am torturing them except THEY are the ones who want to go snorkeling at night, not me! Now if I say Megalodon, that would be a different story.

[Tayana42]

Originally Posted by noelex 77

The 3D side scanning images look amazing. I have zero experience with these, but you would think it would be much better than a conventional fishfinder and very helpful especially in avoiding rock and debris.

Even so it would be no substitute for a mermaid!😉


S/V B'Shert

[JPA Cate]

Evan,

You may do this, too. If your anchor is sliding along the smooth rock, looking for somewhere to dig its toe in, you can feel it sliding along by putting your foot on the chain, the chain transmits the feel of what the anchor is doing. Sounds like you have challenging conditions there. ....And, WELCOME ABOARD, thanks for your post.

Hard coral bottoms give the chain thundery noise, too.

Ann

[noelex 77]

Originally Posted by Tayana42

Even so it would be no substitute for a mermaid!😉

Mermaids have lots of uses

[hoppy]

Originally Posted by noelex 77

The 3D side scanning images look amazing. I have zero experience with these, but you would think it would be much better than a conventional fishfinder and very helpful especially in avoiding rock and debris.

I wish I had that the other day when I was looking for a place to anchor. There were some stunning rock formations where I got stuck which would have made great photos. Would love to snorkel there with the camera, but not with my boat anchored anywhere nearby though