Why are casinos on boats?
I think the recent (last ~15 years) trend started in Iowa, and quickly spread to Illinois, then Missouri, then virtually every state with a river or coastline.
The original logic was that this historic landmark - the passenger riverboat, was dying, and something was needed to save it. Hey, why don’t we let them put a few slot machines on board for extra money?
In Iowa, there was originally a $200 loss limit, and the boats had to cruise for 3 hours (i.e., be riverboats).
Illinois saw that it was working for Iowa, and didn’t want to lose tax revenue to it’s neighbors, so it legalized riverboat gambling, with slightly laxer limitations.
In Missouri, riverboat gambling barely passed, and again, the boats had to cruise for 3 hours, $200 loss limits, etc.
But, soon competition erupted. The early boats were simple - riverboats, not casinos, and began losing business to the purpose-built casino boats. So the early boats petitioned (bribed?) the political leadership for higher limits, an end to cruising, etc. Soon, there was a race to the bottom, and the boats stopped cruising, limits got very high/eliminated, and they became moored casinos.
In Missouri, infamously, we got ‘boats in moats’ - operators built small ponds, a quarter mile inland but more convenient for their development, and then put a structure on these man-made ponds that nominally ‘floated’ (though it had not the slightest resemblance, inside or out, to a boat). This caused an uproar, which conveniently enough for the operators, led to a banning on future ‘boats in moats’, but sanctioned the ones already built. Yes - legalize what I’ve done, but prohibit future competitors.