Prepare to get nickel and dimed on extras
Much like airlines make big bank by charging you for the seat you choose, checked baggage, carry-on baggage, Wi-Fi, TV, snacks, and so on, cruises also rely on extras for profits. In fact, these "ancillaries" -- including alcohol, Internet access (up to $25 AN HOUR!), spa services, specialty restaurants, certain premium food items, yoga classes and wine tastings, excursions, laundry services, even fountain soda and bottled water -- comprise about one-quarter of the largest cruise lines' overall revenue.
You have to tip pretty much everybody on board
You could complain about having to tip everyone, but you could also acknowledge that US labor laws do not apply to ships registered outside of the United States. About 75 percent of the crew works 10-14 hours each day to make your stay more pleasant, while earning just $1,000 per month for doing it. (Though recent changes have set a max on the number of hours worked in a week at 91 hours. Per week.) So yes, you must tip everyone; and you can do so with prepaid gratuity packages, or automated service charges, or cumulative cash tips at the end for those who worked specifically with you, or cash tips along the way for particularly exceptional service. Tipping etiquette can be daunting, so start by reading this. Also, if you've ever wondered what it's like to work on a cruise ship, anonymous employees reveal all the secrets here. It's insane.