If your vessel has zinc anodes that are wearing (white, or losing shape, flaking) or worse, missing (like one of mine), they should be replaced. I found a quality supplier of ‘zincs’, and they don’t charge a shipping charge for orders of over $100 (a common gripe when buying relatively heavy items through the mail).
Try BoatZincs.com next time you need anodes. Chances are, you’ll find the experience to be the well-charted, efficient service I did. And, if you have a question, Angela will dispatch it quickly and cheerfully when you dial the toll-free number to the office!