On my cruise on the Paradise in December,2000, I won about $220.00 at once on a slot machine. Of cource I spent it all and thensome throughout the cruise in one way shape or form. But I got an invite later on in the week to get my picture taken for free in front of the machine that I had won on.
I would venture to guess that cruiseline slots are not at all that loose. Probibly most if not all of them are set to pay out at the minimum % which I believe is 86%.