As to the type of chain, there is an unfortunate amount of confusion. There is high-test (often called Grade 43, made of 1002 carbon steel), BBB (Grade 30, made from 1008 carbon steel) and proof coil (also made with 1008 carbon steel). High-test boasts nearly twice the strength of BBB or proof coil, and thus a smaller diameter can be used, allowing for more scope at an equal weight. BBB is popular due to its lower cost and compatibility with most windlass gypsies. Because of its short links, it “behaves better,” meaning it piles well and is less likely to foul. The misnomer “proof coil” implies that every link has been certified by the manufacturer, as some chains are, but this is not the case. Proof coil often finds a home as a short lead in a rope/chain system, but it should not be considered for heavy-duty windlass-driven work. Vessels that ply extreme waters might opt for a heat-treated high-test, which adds significantly to the chain’s strength but may lose its temper in the re-galvanizing process. Given the extreme areas I have done much of my sailing in, and the aforementioned loss of catenary effect once the chain is pulled taut, I believe the additional strength and length of high-test is well worth the additional cost.