How do you weather a black submarine?

I typically use gray pastels for weathering black or very dark surfaces...the more weathered, the lighter the gray.

Jeff Herne
Modelwarships.com

if you want to simulate some waterline grunge...you can also use some white acrylic mixed with some raw umber, and use a fan blender type brush to add it. Pul the paint down a bit from the waterline and lift the brush at the end of the pull.
If the Typhoons were moored in cold water ports, I would not use any greens to simulate algae growth...too cold.

Try looking for fotos, and try to take something out.
Sometimes is the best but good fotos are hard to find.