Ensuring your anodes are in good condition is without doubt one of the most important maintenance tasks of boat ownership.


what does an anode do

An anode helps protect metal underwater – such as the prop shaft and the engine – from electrolytic corrosion.

Using a sacrificial anode, made from a weaker metal than your boat components, are designed to corrode instead of your boat. They are fitted usually with bolts or bonded to the desired part of the boat.

what anode do i need

The size of the anode is dependent on the size of boat you have and the amount of underwater metal your vessel has.

The material type of the anode required will depend on water type where your boat is to be kept.

Generally speaking, zinc anodes would be most appropriate for salt water and magnesium anodes would be more suitable for freshwater.

Aluminium anodes are most popular in brackish water.

how often should i change them

Anodes should be inspected at least annually and replaced if more than 50% has wasted. Inspection should also include checking the anode is free of any paint and corrosion deposits.

When fitting or replacing a sacrificial anode you should also replace the serrated fan disc washers under the nuts and change the anode backing sheet on wood and GRP hulls. Exposed fixing studs, nuts and washers should be well greased or painted after assembly.

We recommend having a qualified engineer inspect and replace your anodes.

DISCLAIMER: The text, places and opinions expressed in the text above are offered in good faith. Any action taken upon from the information on this website is strictly at your own risk; and Bates Wharf Marine Sales Ltd will not be liable for any losses or damage in connection to the use of our website.