Remember Pirate Radio ?
Remember how it was shut down - not just in UK waters; but well outside the then 3 mile limit ?
What Flag of Convenience flag is this ship going to fly ?
What is going to be done when she has to go of for dry dock ?
Parking a ship off a busy port is going to cost in insurance and P&I club fees.
How are they going to stream a decent broadband connection - along with phone circuits ? Perhaps InMarSat will back them ?
Issuing of tourist visas for Passengers is OPTIONAL for US Immigration.
Crew members are considered to be WORKING and are issued temporary no work; work visas as crew (yes I know; a no work work visa -- it means you can work on the ship; on the dockside for work relating to the ship but no other form of employment). Even then US Immigration can refuse such visas without giving a reason.
Dead head (Dead Head - typically guest of ship; eg crew member's spouse; Ship Owner; and people who know how to blag a free cruise) people are counted as crew for the purpose of immigration (that is why they are signed on to ship's articles). So a visa is again; in the gift of the Immigration service.
I have a feeling their Admiralty lawyer may be a bit late coming to the party.