Boat Sterndrive Anodes
Boats commonly have a lot of metal parts, and water is commonly not that great for metal parts. An anode is a part made out of a metal that corrodes easily; it’s very generous with electrons, which keeps the more expensive, harder to replace, more structurally important parts of your sterndrive set-up from corroding. Anodes are also commonly referred to as zincs because zinc is one of the most commonly used metals. The anode is charged with negative voltage, which causes it to spit out electrodes, which in turn feeds the corrosion that would otherwise be snacking on important parts.Different Metals
There are a few different types of metal used for anodes, and different types might work better or worse for you depending on how and where you use your boat, and what your budget is. Aluminium is the cheapest option, but also the least conductive and therefore the least effective. Zinc is more expensive and more effective, but prone to covering itself in a layer of oxidisation, especially in fresh water, which will stop it from corroding and therefore from doing its job. Magnesium is the most active but also the most expensive. It will get eaten away very fast by comparison to the other two, and in some cases all that activity isn’t necessary and you’re actually over-protecting the other components of your engine. There are also different considerations for open salt water versus brackish water, and polluted water brings its own particular needs and considerations. Where you dock your boat, how many other boats are around, and whether or not you’re connected to shore power are things to keep in mind too. Consult a qualified marine mechanic and have a discussion about how you use your boat and what type of anode is right for you to get the best results.Other Sterndrive Parts
Anodes exist to protect the rest of the parts from corrosion, but sometimes they stop working due to that protective layer or because they corroded away entirely. In those cases, you might suddenly find yourself with other parts of the boat that will need to be replaced to continue safe operation. You can find replacement sterndrive transmission parts to fix problems like that, or get a completely new sterndrive outdrive and sterndrive engine in cases of advanced and severe corrosion.