... to answer that question... I know the rules vary from state to state... early on, some of the boats had to actually set sail and gambling could only take place out on the river... later the boats were required to be seaworthy, but were allowed to stay moored at the dock... and later still they became large barges fitted out as a casinos with no seaworthiness whatsoever. As to the timetable of all this, and the percentages, I will defer to others.