How much chain and what size for my 17'?

[Perithead]

I'm heading down to West Marine this weekend and I plan on buying a section of chain for my anchor rode. Right now I have about 20' that is made up of two 10'ish lengths, I haven't checked the size of it yet.

My boat is a Montgomery 17 (1600lbs displacement) and my anchor is a Rocna 6 (13lbs). I want to have the correct amount of chain to ensure that my anchor holds in rough conditions but I don't want to go to much either.

I plan on doing some cruising down in the Florida Keys and onto the Bahamas in the future so I think I want more chain than the average weekender but I don't want to go overboard on such a small boat.

I am thinking 20' of 3/8"? Is that to much or to little? If it's personal preference then what would you do if it were your boat?

[Squidd]

Is that a chinese rocna...?

Cause if it is I don't think it matters what chain you put on it...

[QuickMick]

here is a decent link if you want to check it out, but I think that given the size of your vessel you are over thinking this. Do you have drouges? Anchor in lazz a stern? Just mentioning that you may wanna consider a bit of redundancy for the types of trips you are talking about, as your rode may out last your line or even bow in total $h!te. conditions.

Ground Tackle: Selecting Anchors and Rodes by Don Casey

fair winds
Q

[SlowButSteady]

As a rule-of-thumb a boat-length of chain is a good minimum. However, the more chain on the rode, the less scope is needed. It becomes a tradeoff between carrying around a lot of heavy chain (usually kept in bow anchor locker, or the stern lazarette; either of which is less than optimal for the weight distribution of the boat), and being able to anchor without a huge amount of scope (and consequently a large swing radius).

[scotthenry]

What I used for my Mont-17 many years ago was an 8-lb Danforth on 35-ft of 3/16 chain and 200ft of 5/16 nylon for the main/bow anchor, and a 4.4-lb (genuine) Bruce on 20ft of 3/16 chain and 200ft of 5/16 nylon for the 2nd/stern anchor. I sailed it (mostly) single-handed around Santa Cruz and Catalina islands, and some up & down the coast from Marina Del Rey in southern California. Most of the places I ended up anchoring bow-and-stern (with everybody else). My biggest problems were occassionally having one of the anchors i the surf at low tide when I wanted to leave... and once when I had to anchor in over 60ft off Isthmus Harbor, Catalina. I always used chafing gear on it, and I did have some chafe at the rope/chain joint, though not enough that I was concerned. A couple of times the Bruce didn't seem to set well, in hind sight I would have gone bigger.

[Gary M]

I believe that 20 feet of 3/8" chain will weigh about 20 pounds, more than your anchor. Way over kill and harder on the back.
Go with 1/4" chain and if you want extra weight make it longer.

[Perithead]

Thank you all for the excellent posts!

My anchor and rode are going to be stored right under the companionway which should be a good place for the weight.

Thanks Scott for the first hand advice! My secondary anchor is a Fortress Stowaway FX-7 that I'll probably put a 10' length of chain on.

Gary, I didn't even think about that. I will definately go with 1/4" chain, at least 20' of it. Ill decide if I get any more by the weight of it (and the price).

[Barquito]

One reason to have an extra long section of chain is to prevent chafe on the rode scraping the sea floor.

Make sure the anchor gear is secured while underway. You wouldn't want to take an anchor to the cranium while being tossed about in the gulf stream.

[klem]

Chain diameter is determined by what is needed for strength. ABYC suggests around 1000lbs design load for a permanent mooring on your boat and 700lbs for a storm anchor. 1/4" chain will have plenty of strength as others have said. The only other reason to go larger would be that larger chain will last a bit longer. Given the size and displacement of your boat, I would stick with 1/4".

For length, chain will help set the anchor and help with chafe. In a mixed rode, a good rule of thumb is to keep the chain longer than the boat so 20' should be good. If you are going to areas (sharp coral) where there are chafe problems, usually all chain is the answer but that likely would not work on your boat due to the weight.