This is an interesting debate. I always like to keep my photographs "as seen", so if I photograph a ship with a mooring rope partly in the way, or a wind turbine in the background, I don't then use photoshop to remove them. That was how I saw the ship. I only use photoshop to straighten or resize a photograph.
However, I wouldn't then post the photograph on here, if I didn't think it met site standards, unless I though it was of exceptional interest, then I would put some comments to say why I thought that.
It's a very subjective issue. Some people think that objects such as buoys, birds, cranes, ropes etc are part of the maritime environment of a ship, and therefore are acceptable. Some sites do accept photographs like this, so if you do as well, perhaps you should post to them. This site does not., some might say unfortunately, but those are the rules.