Corrosion is one of the most common and often least understood challenges in the marine environment. It can develop below the waterline, around propulsion components, or within internal systems long before there are obvious signs of damage.
So how do you know if your vessel is actually protected?
Looking at anodes during a haul-out can tell you a lot, but it doesn't tell the whole story. An anode may look healthy while the vessel is experiencing electrical conditions that reduce the effectiveness of its corrosion protection. Conversely, anodes that are wearing quickly may not simply need replacing—they could be indicating a deeper issue.
Corrosion monitoring helps turn observations into useful information. Measuring electrical potential, checking bonding and isolation, and understanding the influence of shore power, stray currents, underwater metals and environmental conditions can help reveal what is really happening.
This matters because corrosion is rarely caused by one factor alone and is usually a combination of many types of influences. Understanding these risk factors and relationships is key to preventing problems rather than continually repairing their consequences.
For boat owners and marine professionals, even basic knowledge can make a difference. Understanding why anodes wear, or don't wear, and recognising unusual corrosion can help identify potential problems earlier and avoid unnecessary repairs.
Technology is also making corrosion monitoring more accessible. Our laboratory grade Silver-Silver Reference electrodes (MPS.PRE), for example, can measure the electrical potential of underwater metal components and help determine whether cathodic protection is operating within an appropriate range. This is an excellent and simple tool for boat owners and trades to monitoring cathodic protection performance.
For those wanting to take monitoring further, MarineLinx™ by MPS provides continuous insight into corrosion-related conditions, helping identify changes that may otherwise go unnoticed.
Prevention also starts with selecting appropriate corrosion protection. MPS provides free online tools, including the Anode Selector and Maddox Calculator, helping users understand anode selection and make informed decisions based on their vessel and operating conditions.
Ultimately, corrosion monitoring isn't about waiting for something to go wrong. It's about learning what is happening, understanding why, and taking action early.
By improving knowledge and making monitoring and practical guidance more accessible, we can help vessel owners, operators and marine professionals reduce unnecessary damage, extend equipment life, and make more informed decisions that benefit both their vessels and the marine environment.