Mercury - Aluminum Gearcase Anode Corrosion Protection Series Aluminum 8M0177453. Overview. If you've owned a boat long enough, you know corrosion isn't something you notice in a single moment. It creeps in quietly - a little pitting here, a change in color there - until one day the damage is unmistakable. That's why a dependable anode feels like a small but essential promise every time you drop the boat in the water. The Mercury Aluminum Gearcase Anode 8M0177453 delivers that sense of assurance