To the best of my knowledge:
* Disney does in fact own the copyright to the "Flying Dutchman" as depicted, for example,
here. I'm 99.987% certain they've also trademarked design as well. Ditto for the "Black Pearl" seen in the Pirates of the Caribbean movies.
* Therefore, ships attempting to recreate the "Flying Dutchman" or the "Black Pearl" as depicted in the movies -- or anything approaching them -- are ineligible for submission as User Content.
* Furthermore, the ships as depicted in those movies are not true to historical examples from any time period. Ships for Pirates of the Burning Sea are held to a high standard of historical accuracy, adding yet another hurdle to any thought of adding the Flying Dutchman or the Black Pearl to the game.
* That said, if one is willing and able to follow historical precedent AND ensure your work doesn't copy any of the Black Pearl or Flying Dutchman's distinguishing features, one is always welcome to attempt modelling a dilapidated and run-down Dutch warship or Indiaman. It won't look like the Disney ships, it won't be named after the Disney ships, and I can't even guarantee it would be used in the game... but there's nothing to stop one willing to work within these constraints.
There really is nothing further to discuss about this issue. I may not be a copyright lawyer but I've worked with them plenty. A ship model that strives to look like the Flying Dutchman/Black Pearl would not be considered in a court of law to be an original work of art or a parody, it would be considered a violation of Disney's intellectual property. That's not something we're interested in seeing -- for our sake as much as yours. We're here to make a game and not probe every nook and cranny of WIPO or the Uruguay Roudtable Agreements.
To any virtual shipwrights out there: happy modelling!