Last week, I was helping friends replace the rusty old chain that was in the bow of the boat they had just purchased. They knew the chain had to be replaced, but were not certain of how to determine what size and type of chain was appropriate for the windlass on their boat.
Working for many years at West Marine, I found many others who were in the same situation and needed advice on exactly what chain to purchase for their boats. This kind of knowledge is really very simple, and here is a quick lesson in choosing the right chain for your ground tackle.
If you have a windlass already aboard, it’s necessary to have the correct chain in size and style of chain link to be compatible with the gypsy on your windlass. And vice versa — if you’re considering purchasing a windlass, you need to make sure the chain gypsy is compatible with the chain you already have aboard your boat. All windlass manufacturers will have specific chain gypsies you can use with their windlasses.
There are three types of galvanized chain that are commonly used on most cruising boats. Let me explain the differences and how to find out for yourself what is correct for your boat. The first kind of galvanized chain you find in most chandleries is called proof-coil chain. This type of chain has a long link that is not very strong but is commonly used ashore for the many uses of chain. This is the least expensive galvanized chain you can use. It will have a G-3 stamped on each link so you will always be able to tell it is proof coil. Not many cruisers use this kind of chain, but there are windlasses that have chain gypsies for proof coil (G-3) chain. This is generally used on your ground tackle if you only use a small amount of chain backed up by nylon line.
The second kind of galvanized chain, which is most commonly used, is called triple B chain, and will always have a BBB or 3-B stamped onto each link. This is a short strong link that is moderately priced and found on most cruising boats and compatible with most windlass chain gypsies.
The third choice of chain link is high-test chain that will always be marked with a G-4 or HT on each link. This is also a short link but much stronger than triple B (BBB or B-3) chain. This is more expensive than the other two kinds of chain because it is much stronger. Many cruisers use high-test (G-4) when weight is a critical factor and space in a chain locker is limited, like on a catamaran. You can use a smaller diameter G-4 or HT chain and it will be just as strong as a larger BBB or 3-B link. This allows less weight and less volume with the same strength as larger diameter chain like BBB.
Remember when choosing the correct chain for your boat and boat's windlass, that the diameter of the chain is just as critical. Most cruising boats today use 5/16-inch high test (G-4 or HT) or 3/8 inch triple B (BBB or 3-B) chain. There are, of course, smaller diameter links and larger ones as well. However, you must be sure that whatever chain you have is compatible with the chain gypsy on your windlass if you have one, or if you want a windlass make sure the chain gypsy is compatible with the chain you already have aboard.
This sounds a bit complicated, but it really is quite simple if you look at and measure the different types of chain. It's a good thing to carry a caliper with you when purchasing chain so you can measure and find the right diameter and type of chain link.
Determining the right chain for your cruising ground tackle is an important part of outfitting your boat. Let me help you if you have any questions, and enjoy those wonderful days on your anchor!
Pam Wall spent more than 10 years as an outfitting specialist for West Marine, and she now provides her expertise as a cruising consultant and seminar presenter at boat shows around the country. Pam has cruised under sail extensively, including a circumnavigation with her family aboard their 39-foot sloop, Kandarik. Check out her website at pamwall.com.