The current standard is o.k.
I think, if a photo is enhanced in such way, that it makes the ship look natural and does not make the colors etc. look in a way, like it never looks in reality, it is o.k.
It is in my opinion ok, to remove seagulls, some things are in the way, as long it is not possible to see this in a photo.
HDR images, I am against them, because they make the photo look un-natural, the sky and ship look like a drawing and not like they do look in reality. It is good, that these photos are not allowed because this is a page for photos and not for "piece of art". and "playground for photo-editing program".
Framing should also not be, just for the ake of making all photos here look the same.