I’ve been getting into coloring/painting lately and started using alcohol markers. I decided to color a couple cheap nickel blades. I am bery intrigued by the results. Once dry I cant scratch it off. No idea what will happen in water but compared to my efforts with acrylic this seems promising. I am going to clear them with uv and see what happens. I will update the thread with results. 

Forgot to add the blades. I will note the are a coat once thing. I tried adding a second coat and the alcohol in the marker caused the first coat to loosen up and streak faintly. Its really not noticeable unless the light hits them right, but not anything a fish would care about.

I use them to write on reusable dope cards. Very water resistant in some heavy rain. Never tried it underwater but I'd suspect you'd get some good use before it degraded any. 

Check these out:

 

https://www.artlineworld.com/products/artline/special/iregui/elf_f.html