General Off-shore casinos?

Gambling in international waters is this big thing in the movies, especially in crime syndicates. I get seasick on ferries so it really doesn't appeal to me but has anyone here ever done it in real life? What is gambling like on cruise ships, because I have heard it is huge.

It is common to see these scenes in the movies and what a sight this normally is. On the contrary, I have a fear of heights so gambling on a cruise ship would be real fun. At times, these movies make gambling look like a rich man's hobby.