It can be tricky, they say, since newbies are often afraid they'll be bored, held to a strict eating schedule that doesn't suit them or surrounded by retirees. Others have followed the news and are worried about pirates, puking and just plain staying alive.
What could go wrong? Here's a list.
1) 700 people could start puking and have diarrhea
(Roberto Schmidt/AFP/Getty Images)
Royal Caribbean cruises can! Specifically, the Explorer of the Seas (pictured above) holds this record for the most people reported sick on any cruise ship in two decades. Congratulations Explorer of the Seas! That title is according to data from the Center for Disease Control and Prevention, which has a list of outbreaks on international cruise ships.
The official numbers from the Explorer of the Seas' January 2014 trip were as follows: 630 passengers and 54 cruise workers came down with norovirus, the most common stomach bug.
Kim Waite, one of the lucky 630, told CNN that she thought she was the only one on board who was sick until they wheeled her in a wheelchair to a makeshift infirmary where she saw sick passengers everywhere, vomiting in buckets and bags.
"I just started crying," she said. "I couldn't believe it. I was in shock. Because I thought I was the only one that was sick, and then when you see everyone else sick, it really upsets you even more."
The Celebruty Mercury is up there fighting for silver next to the Explorer of the Seas' gold, with more than 400 passengers falling ill to the norovirus in 2010.
2) The engine room could light on fire
(Jeff Gammons/Getty Images)
What was supposed to be a four-day jaunt to the Caribbean became an eight-day nightmare when an engine fire left the ship and its 4,000 passengers floating in the Gulf of Mexico without power, air-conditioning, or a working septic system.
3) You could not be asked to abandon a sinking ship
(Laura Lezza/AFP/Getty Images)
On Jan. 13, 2012, the Costa Concordia struck a rock in the Tyrrhenian Sea on the western coast of Italy. This tore a hole in the hull, which soon flooded parts of the engine room and caused loss of power. The ship drifted toward Giglio Island and grounded in shallow waters with most of her starboard side under water.
You'd think an order to abandon ship would have come post haste, especially given the gradual sinking of the ship and its proximity to shore in calm seas, but the captain didn't order an evacuation until more than an hour after the initial impact. At that point, it took more than six hours to get everyone off the ship and not everyone survived. Thirty-two people died, of the 3,229 passengers and 1,023 crew known to have been aboard.
Five Costa Concordia crew members have been convicted of manslaughter in an Italian court over the tragedy, while the now-infamous captain, Franceso Schettino, has been accused of both abandoning ship and of manslaughter. Engineers are still attempting to pull the vessel upright more than a year-and-a-half after the accident.
4) Pirates could attack
(Punit Paranjpe/AFP/Getty Images)
Passengers on the Seabourn Spirit, a Bahamian-flagged vessel, awoke to the sound of gunfire on Nov. 5, 2005, as pirates fired a rocket-propelled grenade and machine guns at the small luxury cruise liner off the coast of eastern Africa. Two armed, inflatable boats approached the vessel about 100 miles off the coast of Somalia, in waters notorious for pirate activity.
The crew had been trained for such scenarios and was able to evade the pirates without returning fire. One member of the crew was injured by shrapnel while using a giant acoustic device to repel the pirates with a powerful sound wave.
The Spirit had been bound for Mombasa, Kenya, at the end of a 16-day voyage from Alexandria, Egypt. The ship sustained some damage from the grenades, but was deemed safe to continue sailing. After a small detour, it sailed onto Singapore as scheduled. Take that, pirates.
5) A seven-story-high, freak wave could smash into the ship
(Stephen Chernin/Getty Images)
A seven-story-high wave smashed into the Norwegian Dawn off the coast of Georgia on April 18, 2005. The ship was en route from New York to the Bahamas when the freak wave broke windows, sent furniture flying, flooded 62 cabins and injured four passengers.
Passengers got a refund of half the trip’s cost and a voucher for half the price of a future cruise. Um, did someone say future cruise?
Rogue waves also clobbered the Louis Majesty in 2010, killing two people while on a 12-day cruise around the Mediterranean.
6) The ship could roll over
The Titanic has captured the imagination of so many with its epic tale of tragedy in 1912, but very few people have heard of the SS Eastland, a cruise liner with its own claim to catastrophe just three years later.
The SS Eastland literally rolled over, while tied to a dock in the Chicago River in 1915. Eight hundred forty-four people died, most of the women and children. It was the largest loss of life of any shipwreck in the Great Lakes. The worst part? There were known design flaws in the ship that made it suspceptible to listing, especially when passengers gathered on the upper decks.
You can guess where most people were at the time of the accident. Hundreds were also trapped inside by the water when the ship suddenly rolled over. Others were crushed by heavy furniture, including pianos, bookcases and tables.
7) You could have been on the Titanic
The Titanic, which needs little introduction, struck an iceberg and sank, killing more than 1,500 passengers and crew in 1912. That's the last time anyone has advertised a cruise with the moniker, "unsinkable ship."