Corrosion
Photo: Mark Corke
Anodes are essential to protect submerged underwater metals from galvanic corrosion. Normally they should be replaced every year or when they are 50 percent wasted. How long anodes last depends on many factors, such as where you keep and use your boat and whether it stays in the water between uses or is stored on a trailer. Inspecting anodes on a trailered boat is pretty easy, but for boats stored in the water, things are a little more complicated. And because you can't easily see the anodes that are clamped to things such as shafts, line cutters, and bow thrusters, they tend to get forgotten. In some cases, it makes sense to hire a diver to check the condition and, if necessary, replace worn anodes. Doing so may be even more cost effective than hauling the boat out of the water.