sorry for late reply but some fast points:
- Your window color is a bit dark, try instead using the samme window color of those Netherland vessel in the post above yours
- hull shading, you're way of shading isn't totally wrong, but since you have come this far.... see how "Karl94" did his hull shading on USS Tennessee in the post above.
If you let the hull shading in the bow, right before the sonar start to go down, it would illustrate the hull shape a little more correct. there wouldn't be hull shading up the bow. The same shading style most of us use above waterline also apply under water line.
- the railings could be in a darker grey color, so it stand a little more out.
- aren't the any railing around the 40mm cannons and that area?
- some ships have a small railings up with the main radar, does these ships have that to?
- BTW. check that you have all the obvious navigation light.