Good
From another Maya student, here is what I think..
Overall scene: lack geometry resolution. It looks almost everything is a primitive or primitives with boolean. Try putting some bevel here and there at least.
Shot: If this is in a film, you would need to adjust it to the shot. For example put alot more resolution geometry and texture wise on the door near the camera. The camera angle is nice tho.
Shadows. You don't have much of an excuse not to use them, almost just a check box! Overall lighting is a bit odd too.. should come from the ceiling since it's a submarine? it looks much more like a boat, I don't think submarine have windows (real one I mean)..
Nice bumpy-rusty texture (you might want to add specular map on this, for extra cool effect), good job, keep learning man.. maya is a very powerful tool!
cheers!