Well, there was a small cruise ship called the "MV Caribe" that I think was converted to a casino ship in the late 70's, but I can't verify that. The web site below has no mention of a casino.

Also, in Europe, they often will write 5,000 as 5.000, so that may be a five thousand chip rather than a five chip. Now the question is five thousand what? Lira? The Caribe was an Italian ship.

Jeff Wagg R-5774