The Gerald Ford aircraft carrier is under construction right now. A cursory examination of the photograph of the ship in the link shows the ultimate futility of relying too much upon secrecy as a military strategy if you are a superpower that uses weapons like aircraft carriers. You can't hide an aircraft carrier in dry dock. You can have each of the tens of thousands of people involved in its construction sign confidentiality agreements, but you can't seriously expect that those will be honored 100% of the time if someone is really serious about getting information from those workers.
Secrecy is important to national security, but there are real limits to what a superpower with a massive, technology heavy military can accomplish with it.
It is suppose to look like this artist's conception when it is done, but dirtier, with more people and clutter and water on deck.