Zinc vs. Aluminum vs. Magnesium Anodes: Which One Does Your Boat Need?

If you’ve ever looked at the underwater portion of your boat, you’ve likely noticed blocks of metal bolted to the outdrive, hull, or shaft. These aren't just extra hardware—they are your boat's frontline defense against a silent, expensive enemy: galvanic corrosion.
Choosing the wrong boat anodes can lead to thousands of dollars in ruined props, pitted hulls, and destroyed lower units. Let’s break down exactly how to choose between zinc, aluminum, and magnesium for your specific waters.