Dont believe me, then why when you look at the butt of any Carnival ship are they registered in Nassau or similar ports? Not Miami, as they would have to pay US tax.
I'm guessing the lines are using a major loophole here, they appear to be American to you or I, but not in their tax liability, unlike you
While that is "somewhat true" , the main reason they register their ships in foreign countries is to avoid having to abide by US labor laws. They'd have to pay minimum wages and have 40-44 work weeks before overtime payments were required.... which would demand MUCH higher cruise fares in order to make a profit.
But, no question they keep their liquor prices high to compensate for the lower costs of the cruise fare. Which really isn't unreasonable. It's a case of user pay.
And those of us who drink very little enjoy having those who drink more subsidize our cruises, rather than have to subsidize that of those who drink more