Anodes are the cheapest part of your running gear and the only one whose entire job is to be destroyed instead of something else. When they are gone, the corrosion moves on to your propeller, shaft, rudder and trim tabs.
The Barnacle King zinc anode program takes the guesswork out of it. A diver inspects your anodes on every visit, replaces them in the water before they stop protecting, and documents the condition of each one so nothing is a surprise.
How often anodes actually need replacing
The working rule is to replace an anode once it has lost about half its original mass. In warm South Florida salt water that usually lands somewhere between every six and twelve months, but the honest answer is that it varies more than most guides admit.
What moves the interval:
- Salinity. Warm, high-salinity water accelerates the reaction. A boat kept up a brackish river goes through anodes more slowly than one sitting near an inlet.
- Metal mix. Aluminum outdrives, bronze running gear and stainless shafts all draw differently.
- Shore power and stray current. A marina with stray current in the water will eat anodes far faster than the same boat somewhere else, which is often the first clue something electrical needs attention.
- How much the boat runs. Water movement across the anode changes the rate.
This is why we do not sell a fixed anode interval. We check them on every cleaning visit and replace them when the condition says so, which for a boat on a recurring Hull Protection Plan means you are never guessing.
What the program includes
- Inspection on every visit. Every anode on the vessel, checked while the diver is already on the running gear.
- Replacement in the water. No haul-out, no travel lift, no yard slot. The boat stays in its slip.
- Anodes supplied and fitted. Shaft, hull, trim tab, rudder and outdrive anodes, matched to your vessel and the metals on it.
- Photographed before and after, on professional underwater camera equipment, so you can see what was there rather than take our word for it.
- Flagged in your dive report when an anode is past halfway, so replacement is a decision you make with notice rather than a surprise.
Zinc, aluminum or magnesium
The right anode depends on where the boat lives. Zinc suits salt water. Aluminum performs better in brackish water and is generally the better choice for boats that move between the two. Magnesium is for fresh water and will waste away quickly in salt. Mixing types on one vessel, or fitting the wrong one for the water, is one of the more common problems our divers find. We will tell you which your boat should be running.
What it costs
Anode pricing depends on the type, size and number fitted to your vessel, so it is quoted with your cleaning rather than sold off a rate card. Our hull cleaning rates are published in full on the hull cleaning prices page. We are not the cheapest anode service in South Florida and we do not try to be. What you are paying for is that a trained diver is on your running gear every visit, that the work is photographed, and that the anode is replaced before it stops doing its job rather than after.
Book anode replacement
Tell us the vessel, where it is docked, and roughly when the anodes were last done. If you do not know, that is fine, a diver will tell you on the first visit. Most vessels can be added to a recurring schedule on that same visit. Existing clients can see every past visit, the photos and the invoices in the customer portal.