SMALL FISH TYPE ANODE CMT-20

Function and technical context

The minnow sacrificial anode is an essential component of the vessel's cathodic protection system, designed to protect submerged metal parts of the hull, transom, propeller and fittings against galvanic corrosion. Being manufactured with an alloy with a higher negative electrochemical potential than the aluminum, stainless steel or bronze of the components it protects, the anode corrodes in a preferential and controlled manner, acting as a sacrificial element. Without this active protection, galvanic corrosion would directly attack the critical surfaces of the propulsion and hull, causing structural deterioration, loss of propeller performance and costly shipyard repairs. Its compact fish-shaped geometry makes it especially suitable for installations in confined spaces or as reinforcement of protection in specific areas.

When to replace this part?

The clearest symptom that the fish-type anode has exhausted its useful life is the loss of more than 50% of its mass: when it is observed to be very reduced, fragmented or has a very irregular and porous surface, it must be replaced immediately. Sacrificial anodes should be inspected at least once per nautical season—ideally at each beaching or annual inspection—and replaced preventively even if they are not completely consumed, since an exhausted anode leaves the metal surfaces of the boat unprotected. Replacing the anode before it is completely depleted is the most economical preventive measure to avoid serious corrosion damage to propellers, shafts, brackets and metal hulls.