Over time, a chain rode that is used all the time will develop a twist that will create tangles in the chain locker and impede the efficiency of the gypsy on the windlass. The twist comes from inevitable but slight misalignment between the gypsy and the bow roller. A chain swivel between the rode and the anchor will help. But the best solution is to use a notched roller in the bow roller that will align the chain with the gypsy as it comes over the bow. Corrosion that ends up as rust will start to eat a chain rode that is used actively, especially in coral and eventually in rocks where the galvanizing is rubbed off.
Wet chain lying in a damp anchor locker exacerbates the problem.
There is no complete solution, but there are preventive measures that will lengthen the chain's useful life. Make sure the gypsy on the windlass does not wobble under strain or have sharp edges that will chew the galvanizing off the links. Finally, chain that is used aboard a voyaging boat will need to be regalvanized after three years of cruising, a process that can be found in just about any developed port city. Depending on use and deterioration, a chain rode should last voyagers five or more years. For those cruising part time, the chain will last a decade.