Shipbucket

The only thing I disagree on the under water hull, is the use of the color brown. You have a red hull, so you should use red for that.

standard red for hull color
a darker shade of red for shading
a very dark red for any sharp angle or big overhang on the hull.

My I suggest to use a red color more similar to this drawing bellow (oh the rudder on Maya class, should be somewhat similar to the rudder of the drawing bellow)