Anti-Fouling Solution?

Question

I am working on an anti-fouling project which is static. It will be submerged under water for more than 95% of the year. This is a barrage gate and is made of metal. I need an anti-foluing solution which is environmentally friendly. The most feasible option i currently have is using silicon-based paints, which is costly. Any other suggestions?

Base material would be cast iron and aluminum. Thanks
I am looking at CPM anti-fouling paint at the moment, would like for more options.

Answer 1

You're gonna have to be more specific. What kind of metal is it made of? It makes a tremendous difference.