Originally Posted by Petar
Many people in the Marina also hang a clamp on "Grouper" zinc anode due to stray currents causing galvanic corrosion.
If you didn't notice any corrosion on your running gear when you hauled, there likely no need for an additional zinc hung over the side. And unless that grouper zinc is in direct electrical contact with the item(s) you want to protect, it isn't doing anything anyway. Most boaters are pretty ignorant about the causes of corrosion and the "hot marina" is largely a myth. I'd be surprised if those other berthers in your marina actually have a valid reason for their grouper use.