Originally Posted by grumpus

Using a chain in salty conditions, you need to regularly wash off the salt, displace/dry remaining moisture and add lubricant. If that's too much effort, at least keep it well lubricated, it doesn't take long to drip on some oil. Good fenders can help keep salt and grit off the chain. Chains are consumable items, as soon as they get stiff and rusty it's time to replace them, and treat the new one better than the old one: then you might wear it out instead of letting it rot.