Does departure day count as day one of a cruise?
The departure day also counts as day one of a cruise. The days on the cruise usually starts counting from the day booked and that includes the day of departure. You can contact your travel agency for more inquiries.
Sure. Especially if you booked your cruise with carnival. The day you walk on the boat might be the best day of your vacation. Especially if you're out at sea and a generator breaks down.