The definition – an electrochemical response that occurs when two dissimilar metals are in electrical contact with each other in the presence of an electrolyte.
Why does this matter? Water is an electrolyte solution. Electric current constantly flows through our waterways. Several types of metal constantly meet each other any time a boat is in water. Therefore, an electrochemical response will ALWAYS occur when metal is in water. That response is corrosion and it will eat away at the least noble metal. That means a metal with the lower atomic number will corrode sooner than a metal with a higher atomic number when side by side in the water.
That’s why you need a Martyr sacrificial anode!
Stay tuned next week for a more in-depth explanation Anodic versus Cathodic, a heavy metal war!