To Chain Or Not To Chain

[sailhunter]

Well, here goes question number one. I think I know the basic rules for anchors and rode. I see myself anchoring in the Bahama's and other coral bottom situations. Because I will be sailing a Hunter Thirty I feel that thirty feet of chain is the number I am dealing with. The boat currently has twin danforths with twelve feet of 3/8 chain and this boat has been in the islands many times. As a matter of fact this boat has been up and down the coat from Canada to South America and over to England once. I know that many people endorse all chain rode for coral and we had 200 ft of chain on the 44 footer that I crewed. My 30 ft won't comfortably carry 400 ft of chain. I want to go with length of chain same as length of boat times 2 for double hooks on the bow. 60 feet of chain I can go along with. If a majority consensus is 50 ft or 60 ft I will buy into that but not 200 ft per. At the same time has anyone heard of or used a 'Manson super anchor' or whatever it's called. A fellow sailor tells me it's the one I want because it really hooks up and will let me go a little lighter than other plows and it eliminates the need to carry a 'yachtsman' for those special occaisions. All opinions welcome and am anxious to hear from island cruisers. Thanks in advance )

[MMNETSEA]

Scope is the ratio of rode paid out to the depth of the water. The proper scope for all-rope rode in average conditions is between 7:1 or 8:1; Whereas 3:1 or 4:1 ratio is ok if you're using all-chain rode. The key is to keep the angle of pull as close to horizontal as possible. Heavy weather or adverse anchoring conditions demand longer scope.

The Manson is yet another anchor Click here

[sailhunter]

Originally Posted by MMNETSEA

Scope is the ratio of rode paid out to the depth of the water. The proper scope for all-rope rode in average conditions is between 7:1 or 8:1; Whereas 3:1 or 4:1 ratio is ok if you're using all-chain rode. The key is to keep the angle of pull as close to horizontal as possible. Heavy weather or adverse anchoring conditions demand longer scope.

The Manson is yet another anchor Click here

Thanks, their website was what I needed to see. I would say the 'Supreme' is not just another anchor and is going to be on my boat. There was however a misunderstanding of my inquiry about rode. I understand scope and conditions. My question is how much chain rode is required to avoid chaffing on a coral bottom. We had all chain on the Gulfstar but I can't carry that much chain aboard my 30' footer comfortably. How much chain rode do I need in front of my line rode to avoid coral chaffing? The best anchor in the world does no good if you are suddenly no longer attached to it.

[JeanneP]

If your cruising will be in the Bahamas and Eastern Caribbean, I think that 60 feet of chain would be adequate. You should be able to find safe anchorage just about anywhere in 10 feet of water, with a very few exceptions. Our first two years in the Caribbean we had only 15' of chain with no problems or complaints, but Tobago was a problematic island with regard to coral and we knew we were headed for the S. Pacific and so we reluctantly went to all chain rode. With 50 or 60 feet of chain, even in a really foul bottom you can buoy the nylon rode above the bottom. We used small plastic bottles, such as laundry detergent bottles, for that purpose.

A friend has a Manson Supreme and swears by it. I have no experience with it, nor do I personally know of any other boat using it. I think you'll find, though, that the average cruiser will tell you that his anchor is fine/great/wonderful, no matter what that anchor is. A more conservative group of people than cruisers I have rarely encountered.

[MMNETSEA]

No misunderstanding, the question only covered all chain - no mention of rope/chain combination rode. It looks like 60ft of chain is what has been decided as the maximum length to be carried on your Gulfstar, so be it . Therefore all that remains is, what diameter rope should be used in the combination - suggest minimum 1" nylon - length to be determined on what you can carry. The ideal catenary to be achieved is that which ensures that the last links of the chain are off the ground, therefore minimizing chafe , Jeanne's suggestion above re. a float/s - well worth considering.

An excellent site which provides the various formulae for different rode is to be found HERE

[JeanneP]

I think Richard has misunderstood the size of your boat. A 30' Hunter is not a heavy boat, nor does it provide significant windage. I think that 7/16" nylon rode is probably more than adequate, and 1/4" chain should be fine for such a boat.

[MMNETSEA]

In view of the short chain - which if chain only = max depth 15ft - Therefore pluncked for safety. The link gave all the mathematics from which Sailhunter could derive his ideal ground tackle.

[sailhunter]

Originally Posted by MMNETSEA

No misunderstanding, the question only covered all chain - no mention of rope/chain combination rode. It looks like 60ft of chain is what has been decided as the maximum length to be carried on your Gulfstar, so be it . Therefore all that remains is, what diameter rope should be used in the combination - suggest minimum 1" nylon - length to be determined on what you can carry. The ideal catenary to be achieved is that which ensures that the last links of the chain are off the ground, therefore minimizing chafe , Jeanne's suggestion above re. a float/s - well worth considering.

An excellent site which provides the various formulae for different rode is to be found HERE

The site you provided "here" is rich in info but I beseech you to re-read 'to chain or not to chain' and you will realize that the Gulfstar I cruised on is history and I am looking to fit my Hunter 30 with appropriate ground tackle for the Islands and other coral and aggressive bottoms. Lokk forward to hearing back from you.

[sailhunter]

Originally Posted by JeanneP

If your cruising will be in the Bahamas and Eastern Caribbean, I think that 60 feet of chain would be adequate. You should be able to find safe anchorage just about anywhere in 10 feet of water, with a very few exceptions. Our first two years in the Caribbean we had only 15' of chain with no problems or complaints, but Tobago was a problematic island with regard to coral and we knew we were headed for the S. Pacific and so we reluctantly went to all chain rode. With 50 or 60 feet of chain, even in a really foul bottom you can buoy the nylon rode above the bottom. We used small plastic bottles, such as laundry detergent bottles, for that purpose.

A friend has a Manson Supreme and swears by it. I have no experience with it, nor do I personally know of any other boat using it. I think you'll find, though, that the average cruiser will tell you that his anchor is fine/great/wonderful, no matter what that anchor is. A more conservative group of people than cruisers I have rarely encountered.

Thanks. I hadn't really considered 'floating' the nylon rode but as long as I don't alter the scope and approach that would work fine. I guess I'm not going to toss those dedcommissioned dink fenders.

[sailhunter]

Originally Posted by JeanneP

I think Richard has misunderstood the size of your boat. A 30' Hunter is not a heavy boat, nor does it provide significant windage. I think that 7/16" nylon rode is probably more than adequate, and 1/4" chain should be fine for such a boat.

The 7/16 nylon rode is what I agree on and have homework to do on the chain. I was thinking 3/8 chain which bothered me due to mass and weight under way. I will definately look into 1/4" chain for if that is adequate would make me much happier. Thank you for your help.

[sailhunter]

Originally Posted by MMNETSEA

In view of the short chain - which if chain only = max depth 15ft - Therefore pluncked for safety. The link gave all the mathematics from which Sailhunter could derive his ideal ground tackle.

I am pretty sure after reading all that has been presented to me(thanks again) I am going to go with 50' of chain backed up by 150' of nylon for each hook. How do you feel about the 1/4" chain as far as being adequate for the Hunter? It displaces 5 ton with the tanks and cupboards empty. I'd sure like to carry that much less weight than the 3/8" coil I was planning on.

[MMNETSEA]

Sailhunter

Sorry about the Topic Heading "To Chain Or Not To Chain" - I did not catch on to its meaning + Shakespeare ??

Anyway here is the Specification code for Ground Tackle from the Maritime and Coastguard Agency :



For a 30ft boat the code has 8mm (5/16') for chain and 12mm (1/2") for Rope.

For the life of me I don't know why I suggested 1" rope ( maybe because that's what I had on my last boat.)

Richard

[sailhunter]

I can see where the confusion came from whith the title of my question and then mentioning the 44' Gulfstar as my experience in the Islands. Easy mistake and thanks again for sticking with me on this. The chart is perfect. Much thanks to all.