The best thing about cruising on a mega ship? Variety. There is a wide range of cabin categories, from affordable interior cabins to lavish suites. There will also be the standard main dining room and all-you-can-eat buffets that are included in the fare, plus a wide range of specialty dining venues — typically Italian, French, and Asian eateries plus steakhouses and restaurants by a celebrity chef — available for an extra fee. Plus, there are dozens of choices of activities to choose from when you are not sleeping or eating, including many that are available at no extra charge.

Mega ships were designed with all ages in mind: There are pools, waterslides, arcades, and character meet-and-greets for kids; ropes courses, climbing walls, surf simulators, and video game lounges for teens; fitness centers, spas, bars, and casinos for adults. Not to mention mini golf, bowling, Broadway-style musicals, and movies under the stars for the entire family. You'll find that summer vacation, as well as spring and holiday break times, means even more families are on board than usual — and it may feel like the kids have the run of the place.

A mega ship is a floating resort on steroids, so a bit of rowdy fun is to be expected when 1,000 or more passengers let loose around a pool or gather in the main dining room. Expect the thump of DJ music by day and the clamor of slot machines by night; many ships also have giant screens by the main pool and in atriums, blasting music and movies throughout the day and evening. 

Is a mega ship right for your gang, but you're a little worried about getting an opportunity to relax? Most new ships have designated adults-only pools and other quiet zones, such as solariums and secluded sun decks. Many also have exclusive areas, such as The Haven on Norwegian ships, MSC's Yacht Club, and the Havana Suites on Carnival Vista, that act as a ship within a ship. If you book a cabin in these areas, you'll get access to pools, lounges, and even restaurants that aren't always available to other passengers, and are therefore quieter.

Not all ports can accommodate vessels this size. This is especially true in the Caribbean, where only certain islands have docks that measure up. You'll find that St. Thomas, St. Maarten, Grand Cayman, and Puerto Rico are standard ports of call.

It’s inevitable: When thousands of passengers all need to get on or off a ship in a limited period of time, there will be bottlenecks. Cruise lines know that no one wants to start their vacation frustrated and impatient and have tried to streamline the process, especially on larger ships. Royal Caribbean, for example, allows passengers to complete much of the check-in process from home, significantly cutting down on wait time at embarkation. On board, popular attractions like the zipline and waterslides attract crowds at peak times, especially on sea days. Try to go early in the morning or at prime meal times to avoid the crush.

These ships are enormous, so you need to be prepared for a lot of walking. It's also smart to factor in the amount of time it will take you to get from place to place. You don't want to miss the start of the show because the theater is a full mile away from where you are having dinner. There are usually three elevator banks (forward, middle, and aft), and you'll want to be aware of which one is closest to your stateroom. The first time you take a less convenient elevator by mistake and look down that long corridor toward your forward cabin, you’ll wish you’d packed your Fitbit.

Some of Royal Caribbean and Norwegian’s largest ships have more than 20 dining venues — and almost as many lounges and bars — so it’s impossible to sample them all on a seven-night cruise. Do your research in advance and make a list of the places that you really want to hit, and make reservations for as many as you can as soon as you book your cruise. That guarantees you'll get to try your top picks and won't disembark disappointed.