Anodes

Our Anodes range covers sacrificial anodes for cathodic protection – zinc, aluminium or magnesium fittings that corrode in place of your boat’s more valuable underwater metal fittings, shaft, propeller and hull hardware.

An anode works by corroding preferentially: it’s a less noble metal than the fittings it protects, so galvanic corrosion attacks the anode first rather than your propeller, shaft, sterndrive or through-hull fittings. Material matters and depends on where you moor: zinc anodes are the standard choice for saltwater, aluminium anodes work in both salt and brackish water and are increasingly preferred as a more environmentally friendly option, while magnesium anodes are specifically for freshwater use, where zinc doesn’t corrode effectively enough to protect anything. Check anodes at least once a season and replace once they’re roughly 50% consumed – waiting until they’re fully gone means your actual fittings start taking the corrosion instead, which is a far more expensive problem to fix.

Match anode size and type to your specific fitting (shaft anode, hull anode, engine anode) rather than assuming one size fits all applications.

Frequently asked questions

What type of anode do I need – zinc, aluminium or magnesium?

Zinc for standard saltwater use, aluminium for salt or brackish water (and increasingly preferred environmentally), magnesium specifically for freshwater, where zinc doesn’t corrode effectively enough to work.

When should I replace an anode?

Once it’s roughly 50% consumed, not when it’s fully gone – a fully consumed anode stops protecting the fittings behind it, which then start corroding instead.

Do I need different anodes for different parts of the boat?

Yes – shaft, hull and engine anodes are typically different products sized and shaped for their specific fitting, so match the anode to the application rather than assuming interchangeability.