How Much Chain, Really... In Non-Rock and Non-Coral Areas?

[Benz]

I anchored all over the Western caribbean and US east coast with 25' chain spliced to 5/8" rope, with a light boat. It's fine for a light boat, and while we're not supposed to discuss chafe, I did have to leave anchorages several times lest coral heads chafed my rode. There was a lot of yawing at anchor which I do not have now with a heavy boat and all chain. However, next time I buy chain for my current boat I'll get half of the 200 feet I have now. I simply don't use more than 100 feet. I do sleep better knowing my chain won't chafe as it grounches on rocks in the middle-north latitudes I've cruised most lately.
As for anchor/chain weight, I think a really heavy anchor with rope is better than a light anchor with all chain.

[dfelsent]

Correct me please:
In relatively shallow water, let’s say 9-13 feet with tide and the bow 5 feet up so 14-18 feet bow to bottom.
Let out 60 or 70 feet of chain. Tie on a 60 foot snubber. Scope is now somewhere around 6.5 to one. Let out a bunch of chain so there is a loop that does not come tight when the snubber stretches.
The rode is now chain/rope with a chain kellet at about the midpoint.
I’ve done this but never in big breeze.

In guess what I am saying is that a long snubber in shallow water turns all chain into rope/chain with a kellet.

[MathiasW]

Originally Posted by dfelsent

Correct me please:
In relatively shallow water, let’s say 9-13 feet with tide and the bow 5 feet up so 14-18 feet bow to bottom.
Let out 60 or 70 feet of chain. Tie on a 60 foot snubber. Scope is now somewhere around 6.5 to one. Let out a bunch of chain so there is a loop that does not come tight when the snubber stretches.
The rode is now chain/rope with a chain kellet at about the midpoint.
I’ve done this but never in big breeze.

In guess what I am saying is that a long snubber in shallow water turns all chain into rope/chain with a kellet.

Yep, it does!

[Jim Cate]

We keep talking about swing circles vs crowded anchorages... but crowds are not the real problem, for to a first approximation, all the crowd will swing in a similar fashion, so the problem isn't a severe one.

But in a hell of a lot of the anchorages we've been in over the years, the physical dimensions of the anchorage's "good" areas (ones without hazards and with good holding) are too small to allow huge scopes. To me this suggests that shorter and heavier chains might be the better choice for long term cruisers, ones that must anchor in lots of different places, some of which are not optimal for long scopes.

And of course, this also argues against rope.chain combos.

Jim

[Slainte1]

I sail a trimaran where weight is important so I use 30' chain and stretchy nylon multi plait.
The chain is the weakest link. Catenary is non existent when it blows hard enough and stretch in the rode reduces shock loads so will stick with present system until persuaded otherwise

[Burnside Style]

I am interested in where this thread is going..
Wife and I are building a small coastal cruising catamaran (Duo 480c)

I am wondering what sort of setup we will need for anchoring this little cat.
Will be mostly be sailed in the Gulf of Mexico anchoring near shore (gunk-holing)


I was a runner up in the recent Mantus giveaway, so I am looking to use my winnings (discount) on either their 8lb or 13lb galvanized steel M1 anchor.


Any ideas as to how much/what size chain and rope we will need?
-Lightweight catamaran (about 1,000lbs loaded)

-Mostly used for long-weekending around the Gulf of Mexico between MS-Fl
-Looking at Mantus M1 8 or 13lb

[Slainte1]

Mantus 8 ib should be fine

[rslifkin]

Originally Posted by Jim Cate

We keep talking about swing circles vs crowded anchorages... but crowds are not the real problem, for to a first approximation, all the crowd will swing in a similar fashion, so the problem isn't a severe one.

But in a hell of a lot of the anchorages we've been in over the years, the physical dimensions of the anchorage's "good" areas (ones without hazards and with good holding) are too small to allow huge scopes. To me this suggests that shorter and heavier chains might be the better choice for long term cruisers, ones that must anchor in lots of different places, some of which are not optimal for long scopes.

And of course, this also argues against rope.chain combos.

Jim

If the chain portion of the rope/chain combo is long enough, then unless these anchorages are super deep, it should still work fine. In the crowded places, you'd typically end up with little to no rope deployed, but you've got it for extra scope in places where you're able to (and want to) deploy more.

[thinwater]

Originally Posted by Burnside Style

I am interested in where this thread is going..
Wife and I are building a small coastal cruising catamaran (Duo 480c)

I am wondering what sort of setup we will need for anchoring this little cat.
Will be mostly be sailed in the Gulf of Mexico anchoring near shore (gunk-holing)


I was a runner up in the recent Mantus giveaway, so I am looking to use my winnings (discount) on either their 8lb or 13lb galvanized steel M1 anchor.


Any ideas as to how much/what size chain and rope we will need?
-Lightweight catamaran (about 1,000lbs loaded)

-Mostly used for long-weekending around the Gulf of Mexico between MS-Fl
-Looking at Mantus M1 8 or 13lb

That's an interesting boat. Someone is going to say "that isn't cruising" by their definition. Perhaps. But it is your situation. I cruised many thousands of miles in a Stiletto 27, up to 2 weeks at a time. Could have gone farther, but dang, there is always work and school for the kid.






There is no one answer to the question. I've used the 13-pound Mantus on a 1500-pound F-24, so I would think the 8-pound would be fine. You will also want a second anchor. A Guardian F-7 would be a good choice.



About 8-12 feet of 1/4-inch chain with 3/8" nylon will do for rode. Technically thinner would be strong enough, but you want the heavier rope for grip and cut resistance, since you aren't using much chain.



How long? I don't know the depths. If you are going to anchor very shallow, 100 feet may be enough. HOWEVER, be warned that you NEVER anchor in shallow water if there is wave exposure. It can turn into surf and you will be destroyed. Therefore, you need at least one rope that will let you anchor in 20 feet with good scope (say, 150 feet). the other rode can be shorter. The thing is, extra rope can be darn handy for pulling the boat off and shore lines.



You will want a bridle. With cats this is critical to getting them to stop yawing. You have a lot of windage forward. Rudders up at anchor will help.


Sounds like fun!

[thinwater]

Originally Posted by Jim Cate

We keep talking about swing circles vs crowded anchorages... but crowds are not the real problem, for to a first approximation, all the crowd will swing in a similar fashion, so the problem isn't a severe one.

But in a hell of a lot of the anchorages we've been in over the years, the physical dimensions of the anchorage's "good" areas (ones without hazards and with good holding) are too small to allow huge scopes. To me this suggests that shorter and heavier chains might be the better choice for long term cruisers, ones that must anchor in lots of different places, some of which are not optimal for long scopes.

And of course, this also argues against rope.chain combos.

Jim

You are right. I've used all chain and like it fine. It has lots of advantages. If I can bear to fit a windlass, I would use all-chain every time.

I started this thread for small cruising boats that are not cruising long term and do not have windlasses. Different.

---

I mentioned using a loop of chain as a kellet. I've done this on light multies specifically to control swing when anchored tight with boats on all chain. It works and prevents conflicts. It also prevents keel wraps.

The other thing to consider is that many of these smaller boats can fit into shallow waters you cannot. Many a time I have anchored inside larger boats, sometimes setting two anchors to avoid swinging out into deeper water.

Different boats, different long splices. I've done both.

[noelex 77]

Originally Posted by thinwater

I started this thread for small cruising boats that are not cruising long term and do not have windlasses. Different.

The cruising ground makes an enormous difference.

Our first yacht was small (26 feet), had no anchor windlass and was not cruised full time. We still often carried heavy anchors and all chain rode. Much of the reason was time spent in offshore locations with challenging wind conditions, poor protection and the requirement to try and match as closely as possible the swing characteristics of larger vessels. Some of the locations had a coral substrate where of course chain or predominantly chain rode is required.

We also sometimes cruised a lake system that had shallow anchor depths with an easy mud substrate much less wind and more shelter. Here minimal anchoring gear was fine and we adjusted our equipment accordingly.

Sometimes we raced and carried a small aluminium anchor with almost all rope rode (I think the regulations required 5m of chain).

So my take is that the ground tackle needs to match the cruising location. If you want to take a small cruising boat into difficult conditions you still need good anchoring gear. That does not mean not prioritising techiniques to reduce ground tackle weight as much as possible but unfortunately there are limitations.

The vessel in post #24 is, I suspect, unlikely to anchor overnight in difficult conditions so the anchoring gear can be chosen accordingly. However, it is wrong to assume all similar sized boats would necessarily have have the same constraints. Small boats can undertake adventurous cruising.

[Thumbs Up]

A long rope rode stretched tight (no catenary) in an anchorage busy with outboard powered boats is just waiting to get that rope sliced by the prop of a boat that drives by too close. For this reason I increased the amount of chain so that I am normally anchored on all chain (at least to where I attach my bridle). Not having to worry about the rope to chain splice is another reason to go with all chain (or all rope) but not having a windlass negates the need for the chain to rope splice (you don't have to get it through the hole). Having all rope negates the need for a windlass. Having all chain and no windlass means that you would need some pretty light chain (and gloves). Having a mixed rode (chain spliced to rope) really sucks with a windlass for a number of reasons (both lowering and retrieving). It is true that rope can have a greater breaking strength than the chain that it will replace but in tension that rope could very easily be cut. This is a trick question, there is no good answer. I am going to say all chain (not oversized but preferably high test).

[thinwater]

A rope-to-chain splice is REALLY easy to learn, no more difficult than the eye splice (a standard chain splice is just a slightly modified eye splice). This should not be a deciding factor, either way.

Heck, I splice it even when I don't have a windlass because it is one less failure point (shackle), easier on the hands, and there is less chafe (the splice cannot move on the chain, whereas a shackle requires a metal thimble spliced in (see--you have to splice anyway--no big deal).

[MicHughV]

to me the issue is kinda moot.

in any anchorage you are likely to get a dozen or more boats...different lengths, different hulls, different skippers, etc, ad infinitum.

no two boats are likely to have the same anchorage system, be it rope, chain or any combo of the above, and anchor types can run from one extreme to another and each skipper is likely to deploy what has worked best for him, be he a pro or a newbie, using one anchor or two, etc, etc. On the far end of the scale, bottom holding is a topic all of it's own.

some will use 10:1 scope others 5:1, etc, etc.

some boats swing to an anchor and some are rock steady.

there is simply not a one size fits all here...

I know what works best for me and it's the same system I've used on different boats over 40 years and no amount of discussion, modeling, formula's, theories, or otherwise is likely to have me change anything.

I don't think I'm alone in this view.

[Thumbs Up]

I am not knocking the splice itself, I have redone mine a few times due to a rusty looking end link although some chain rope combinations are very hard to splice (big line vs. short links) The problem is handling the rope portion. On my windlass you have to get all of the rope stuffed into the hole, along with the splice before you can get the chain onto the gypsy. It would be easy to lose a finger in the process. With all chain, a windlass, and a cockpit switch you pretty much have remote control of the anchor, an enviable feature (but has it's own set of problems too)