The cruise lines do not adjust the slots. First of all it would take longer than the time that they are closed. It just boggles the mind how many people think there is a " best time " to play a machine, or sit down at a table.
There is no best time. Either you will be lucky and win or unlucky and lose. It is exactly that simple. The casino is there to make money for the cruiseline. Even a small house advantage on a game is huge money for them.
The casinos on the ships use Las Vegas Rules. That means that the payouts have a certain minimum. If I remember right ( and who knows its early ) the slots will pay back at least 85% over the life of the machine.
That does NOT mean that if you put in $100, you will only lose $15. It simply means that the house can expect a 15% profit off the machine over the life of it. I have seen with my own eyes a machine hit top jackpopt 3 spins in a row, then not hit a darn thing for a year.
As for the tables, there are too many things that can change the outcome in blackjack. Do they have the endless shoe? Did someone take a hit that they really shouldnt have? Number of players, number of decks and so on. Belive it or not the way and number of times that the dealer shuffels the cards has an effect.
Anyway you look at it. Have fun, dont bet more than you can afford, when you are up, GET UP, if you lose quickly, GET UP.
The most important thing.....TIP THE DEALER YOU CHEAPSKATES!!!!!!!