When planning a cruise vacation, the reality of hidden costs for seemingly innocuous items and activities are often overlooked until the traveler gets the final bill. Bill shock is a common occurrence for passengers who assume that everything is included in the cruise package, which can take the joy out of an otherwise relaxing and fun vacation. To avoid this kind of surprise, it pays to figure out your budget and do your homework before you book your cruise vacation.

First things first, when you see an advertised price for a cruise vacation that seems almost too good to be true, make sure to actually speak to a customer representative so you can get a clear idea of what the accommodations actually are for the promotional price. Cruises like to use “lead-in” pricing, which means the advertised prices are for the cheapest packages on offer rather than for the average cabin on the ship. This sales tactic is designed to attract bargain hunters, but when you find out what’s actually included (or rather, not included), you may want to reconsider your budget or continue shopping around for other cruise packages.

Another important consideration for your cruise vacation budget is the cost of gratuities. In the past, it was common practice for passengers to submit tips in an envelope to the appropriate crewmembers. Nowadays, cruise lines will just add a per day charge to cover gratuity, which can be around $10 to $12 per passenger. While some vacationers may not be comfortable with mandatory gratuity, this is done for everyone’s benefit; passengers can expect assistance from any crewmember, just like crewmembers are expected to help any passenger that requests assistance.

Alcohol and soft drinks can cost you if you drink away without looking into what your cruise package actually includes. Before booking your package, make sure that the customer representative clearly explains what is covered in the price. You can always buy additional drink packages, so you won’t have to worry about an outsize bill once your vacation is over. Many cruise lines offer unlimited alcoholic packages but beware, out in the open sea, just make sure you are surrounded by friends and crewmembers so you are safe no matter how drunk you are.

Internet access is another cost to watch out for. Cruise ships often charge by the hour, and while $0.75 may not be a lot, it can add up very quickly. The age of the ship can also affect the quality of the Internet connection, so it may be a good idea to explore data plans being offered by your mobile phone company. Nowadays, major telecom companies are offering data plans with roaming, which should offer a reliable signal for a preset cost almost anywhere in the world.

When booking shore excursions, you may be tempted to book through the cruise line to save time and hassle. What you won’t be saving, however, is money. Cruises often charge much more than independent operators, which means you will have less money for everything else. In addition, excursions booked through the cruise tend to be crowded and impersonal. Nowadays, independent providers will offer worry-free guarantees to ensure that you get back to your ship on time, so you never have to choose between saving money and having peace of mind.

The key to keeping the costs of your cruise vacation within striking distance of your planned budget is preparation and staying informed. A good rule of thumb is to never assume, it never hurts to ask, and as always, read the fine print. If anything is unclear, make sure the customer representative gives you an explanation. Though preparations can be quite time consuming and maybe even a little stressful, the freedom from bill shock will at least go a long way towards ensuring a smooth and relaxing vacation.