They have a reputation for being a little boring, or plain, but sailing to distant shores on a luxury cruise ship is still very popular.
Most people believe that these all-inclusive vacations are a good value, and it's hard to compete with those ocean views.
But sadly, 10% of cruise travelers who responded to a poll on the review website Cruise Critic said they were involved in an incident on their trip.
These unfortunate problems - ranging from sickness to robbery and even disasters at sea - can totally derail your vacation.
Here are six of the most common risks on-board a cruise ship, and how to avoid them.
1. Theft And Other Crimes
Cruise ships now have their own security crews, CCTV cameras, and other modern features to protect passengers.

But that doesn't prevent unruly travelers from robbing their neighbors, starting fights, and getting into other kinds of trouble.
Locking your cabin door any time you leave is essential, and you should stow any essentials inside your room safe.
There are other times to be watchful too: don't take your eyes off your drink at the bar or nightclub, keep cash tucked out of sight in your wallet, and be wary about new passengers who want to become fast friends.
Think of your ship as a crowded neighborhood in a major city, and take all the precautions you normally would during a night on the town.
2. Food Poisoning And Other Conditions
Cruise ships are notorious for outbreaks of contagious illnesses, and there have been plenty of highly-publicized cases.

Norovirus (which causes diarrhea) and E. coli are well-known for spreading at the buffet, but there are also colds and flus, regular food poisoning, and even sea sickness to worry about.
Most cruise ships have their own doctor's office, but you can expect to pay out of pocket for treatment, which is just another reason to pack some emergency cash and sign up for travel medical insurance.
Plus, not all ship doctors have the kind of certifications and credentials doctors have in America.
Bear in mind that if you get sick on the ship, the crew may quarantine you to protect other passengers, so practice good hygiene or else your vacation could be spoiled.
3. Dangers Off The Ship
Sometimes, the best part of a cruise is stepping off your boat to explore one of the foreign ports where it docks.
Most local businesses are happy to welcome tourists for a drink or bite to eat, but other locals will prey on careless visitors.
Be mindful when showing money around beggars and buskers, and be on the lookout for con artists who single out ship passengers.
While exploring new places is fun, it's always safest to stick to busy "tourist" spots, and do most of your drinking on the ship, where the crew is looking out for you.
Take care when choosing day trips and excursions off the ship as well, because even ones selected through your travel agency can be targeted by thieves.
4. Slips, Falls, And The Open Ocean

It sounds like something out of a Three Stooges routine (or a Goldie Hawn movie) but falling off a cruise ship is no joke.
It takes a long time to get used to the movement of a ship, and even a huge cruise ship can sway very suddenly in bad weather.
No matter the conditions, keep your distance from the guard rails, especially if you're not sober.
If you see anyone else climbing the guard rails - even other adults - warn them to get down. It's better to be a party pooper than to watch someone lose their life.
Make sure to pack at least one pair of sturdy running shoes with good grips. Odds are at least one day of your trip will be rainy, and the wet ship deck can be treacherous.
5. Fires And Other Disasters
While the other risks on this list are more common, serious incidents including fires, storms, crashes, and sinkings are all cause for concern.

Every cruise begins with a security briefing that includes details about ship evacuations and other safety measures - pay attention and don't skip it!
Follow along with every drill the crew orders, and try to actually remember the safety information they tell you. It just might save your life.
You can do your part to prevent fires by minding your cigarette butts and unplugging any electronics before leaving your cabin.
Don't be afraid of being a killjoy, if you smell smoke or see other signs of trouble, report them right away.
6. Modern Pirates
Believe it or not, pirates are still sailing the high seas, but they're not sporting eye patches and talking parrots.

Cruise passengers from South Africa learned that the hard way in 2009, when pirates opened fire on a ship's crew off the coast of the Seychelles.
While the hijackers were later caught, and no one on board the ship was harmed, the risk of piracy is one more reason to question that planned cruise vacation.
If pirates choose to attack your ship for money, there's not much you can do to repel them - but following directions from the crew will keep you safe.
Researching your ship's route can limit your risk in the first place, since most hijackings happen off Africa's East Coast.