What material is often used for sacrificial anodes?

Zinc is the material commonly used for sacrificial anodes due to its electrochemical properties. Sacrificial anodes work by being more anodic than the metal of the hull or another structure they are intended to protect. In the presence of moisture or an electrolyte, zinc has a higher oxidation potential than many structural metals, making it effective in corroding preferentially. This means that when zinc anodes are installed, they corrode in place of the metal they're meant to protect, thereby extending the life of critical components of the vessel.

Additionally, zinc anodes are suitable for use in both freshwater and saltwater environments, which makes them versatile for various marine applications. Other materials like aluminum can also be used for sacrificial anodes, particularly in certain circumstances, but zinc is the most widely accepted and utilized material in marine applications due to its effectiveness and cost efficiency.