You've made a big investment by choosing to own a boat, and it's very important that you protect that investment by properly maintaining and caring for your vessel. One of the most essential maintenance tasks you can perform is regular replacement of the anodes on your boat.

What are anodes and why do I need them?

When your boat hits the water, the metal hardware that is located underwater is exposed to a reaction called electrolysis.  This is a reaction between chemicals in the water and the metals on your boat.  This reaction is corrosive to those metals.  Without proper protection, the metal hardware coming in contact with the water can deteriorate quickly.  Propellers, shafts, aluminum hulls, bow thrusters, engine lower units and more are all at risk of being corroded and irrepairably damaged.

To mitigate the process of electrolysis, anodes are attached to the hardware to attract the electrolysis instead.  Anodes are metal alloys that are composed specifically to attract the electrolysis first before the metal hardware on your boat, so the anode will corrode first.  In this way, the anode is sacrificed for the protection of the hardware it is attached to, which is why they are often referred to as "sacrificial anodes".  However, because anodes are constantly working and being corroded to protect your boat, they will have to be replaced on a regular basis.

So, different types of anodes are needed for different types of environments?

Yes! As mentioned above, zincs are fine for salt and brackish water, but aluminum anodes are even better and can last longer.  Magnesium anodes must be used in fresh water.  Do not use magnesium anodes in salt water as they can actually speed up corrosion rather than slow it down.  Zinc and aluminum anodes are ineffective in fresh water environments. Even though they are made of different materials, these different alloys look similar, so it is very important that you select the correct anodes for your application.  Color-coded packaging is often used to easily identify the different alloys.

How many anodes do I need?

Your engine lower unit has specific shapes and sizes of anodes, so you'll want to consult your owner's manual (or the ABYC-certified experts at Marine Parts Source!) to identify the correct anodes for your engine application.  The specific engine anodes can be bought separately, but if you're replacing one, you likey should be replacing them all.  That's why anodes for popular engine models are often sold in kits.

Hull anodes, rudder anodes, shaft anodes and more can usually be replaced based on the boat builder's specifications.  If the boat builder attached an anode on a specific spot, you should replace those same anodes exactly.  Again, each of these types of anodes come in different sizes, so make sure you purchase the right size and material for your specific application.

I'm still not sure what anodes I need - how can I get help?

Just call us! The salespeople that answer the phone at Marine Parts Source are experienced and knowledgeable, and most of them are ABYC-certified.  We can answer your questions, make suggestions on the best solutions for your boat, and of course, take your order!  You can reach us at 866-388-0390.