How often should anodes be changed?
Marina electrolysis eats anodes faster than you would think. How to read the wear and when to act.
Why they go so fast here
Anodes protect your shaft, propeller and stern gear by corroding first. In a busy marina with shore power on every pontoon, they can go faster than the calendar suggests. Warm water speeds it up again.
In short
- Replace an anode when about half of it has gone, not when it disappears.
- In Maltese marinas, check every six months and expect to replace yearly.
- Use the right material: zinc or aluminium for sea water, never magnesium.
Reading the wear
A healthy anode wears evenly and looks pitted. If it looks untouched after a year, it may not be making electrical contact and is doing nothing. If it has vanished in a few months, something on board or on a neighbouring boat is leaking current, and that is worth finding.
Left to right: new, time to replace, left too long.
What we do on a care visit
On every care visit we photograph the anodes we can reach from the surface. On haul-outs we photograph and measure each one and replace any past half.
Need this done on your boat?
Antifouling & haul-out
Anodes replaced and recorded at every haul-out, by a diver in between.