Anchor Chain revisited

[Texasmark]

Periodically the subject comes up and author of the post gets numerous answers from the following herein. I was watching a movie the other day and it was taken in the waters around Greece. The boat was stopping and anchoring and the camera remained on the Capstan and the anchor line paying out. I noticed that before the line started moving that it was preceded with a chain and expected that. What I didn't expect was the length. For a few seconds I thought that the yacht had all chain. The chain started moving very fast and it took several seconds before the rope line appeared. Going to guess the chain was somewhere around 20-30'. Guess that's what it takes on big boats in deep water......makes sense.

Mark

 

[bruceb58]

Rule of thumb is 6' of chain for every 25' of water depth. Some say length of the boat.

 

[JoLin]

Bruce, where did you find that rule of thumb? I think it'd vary WIDELY depending on the sail area and weight of the boat.

I routinely anchor in about 15-20' of water, sand or mud bottom and winds 10-15 knots. I didn't feel the 10' of chain I had on my previous boat (27' express cruiser, about 8,500 lbs fully loaded), would suffice for the additional 1000 lbs and increased sail area (flybridge) of my current boat. When I ordered my new GOOD windlass I had them splice 20' of chain to the new rode, instead of the 10' they normally supply on 1/2" line.

My anchor sets fast and holds great. As with anything else, though, you can overdo it. If you have an anchor windlass you have to be sure it's powerful enough to drag all that chain up from the bottom.

(by the way, a friend with a 36' Trojan has an ALL chain anchor rode.)

 

[bruceb58]

Bruce, where did you find that rule of thumb?

Here is one place:
http://fortressanchors.com/resources/faqs
Go down to "How much chain should I use?"

As usual, rules of thumb are for average cases. My parents had a boat your size and they used similar length of chain that you do.

I have around 20' of chain for my 24' boat and I use a Fortress anchor.

 

[shrew]

There are many, varied opinions on this with as many variables to consider. IMHO, I would go with a minimum of 1 boat length. I've seen everything from all chain rodes, to all line rodes with no chain. Either does work fine in most conditions. I sleep overnight on anchor at least 50+ nights a summer. I'm upgrading my 30ft of chain to 100ft of chain on a 30ft LOA weighing 8500lbs. It'll go nicely with my 25lb anchor.

Is that too much? I hope it is.

 

[tpenfield]

Typically, you want as much chain as you have boat. . . . Until you get up into the 40 + footers, then you may see only chain as the rode and no conventional line.

 

[alldodge]

I think you will be fine, my opinion that are anchors that continue to dig deeper as the start to move with increased strain are Plow, Danforth and Navy are best in sand, mud and loose rock. Anchors which hold best in large rock, stumps, but will not go deep if they start to move are grapple and Bruce.

So when you go back to your sand and rock your grapple will not hold as well as your Danforth

 

[JoLin]

There are many, varied opinions on this with as many variables to consider. IMHO, I would go with a minimum of 1 boat length. I've seen everything from all chain rodes, to all line rodes with no chain. Either does work fine in most conditions. I sleep overnight on anchor at least 50+ nights a summer. I'm upgrading my 30ft of chain to 100ft of chain on a 30ft LOA weighing 8500lbs. It'll go nicely with my 25lb anchor.

Is that too much? I hope it is.

I'm sure you considered this already, but I'd be concerned about 2 things- first, if my windlass is made to haul that much weight on a regular basis; and second, what I'd do if the windlass became badly jammed or broke down completely. I couldn't manually retrieve that much chain.

The friend I mentioned with the all-chain rode did have his windlass fail with about 80' of chain deployed. Fortunately, when he explained his predicament to the local Boat Tow operator, BT came out with an extra hand aboard to help retrieve the rode. Just sayin'.

 

[Texasmark]

Rule of thumb is 6' of chain for every 25' of water depth. Some say length of the boat.

I know little about the waters around Greece but I think they are in the order of thousands of feet since the Agean sea and lots of other places are just volcano tops that protruded out of the water.

 

[bruceb58]

I know little about the waters around Greece but I think they are in the order of thousands of feet since the Agean sea and lots of other places are just volcano tops that protruded out of the water.

That would make it tough to anchor, wouldn't it?

 

[Texasmark]

That would make it tough to anchor, wouldn't it?

Yessssss and require a lot of chain.