I braced myself—mentally preparing to fight overwhelming crowds and wait in long lines. Yet I boarded in barely 10 minutes and, once on deck, I discovered on-ship “neighborhoods” that helped break up this enormous vessel. A couple of my favorites were an open-air Boardwalk with carousel, ice cream shop and toy store, and Central Park, a lush garden with 12,000 plants, vines, flowers and trees—yes, live trees—with winding pathways and multiple food and drink options. As we sailed through the Caribbean, the ports became secondary. This cruise was about the ship.

Since then, I’ve embarked on other megaship voyages. And today’s megaships are growing, becoming even more mega, so let’s break it down.

There is no definitive calculation for what constitutes a megaship; the numbers are a moving target as the average cruise capacity overall trends upward. And not each cruise line may adopt such terminology. But let’s define the threshold as vessels carrying more than 4,000 passengers. By this metric, five major cruise lines that are actively marketed to U.S. vacationers—Royal Caribbean, MSC, Carnival, Norwegian and Princess—combine for a total of about three dozen megaships in their fleets. Royal Caribbean is particularly invested in this trend, with seven vessels that are each able to carry more than 5,000 passengers.

“The competition wasn’t other cruise lines,” says Gene Sloan, cruise editor at the website The Points Guy. “It was all types of vacations, especially Vegas and Disney World.”

And so these megaships offer a wealth of onboard activities catering to cruisers of every age, which makes them ideal for multigenerational family groups. Megaships typically all have a spa, casino, water park with slides, plus theaters staging Broadway-style shows. But each line has a few standout features distinguishing its ships from the competition. On five of Norwegian’s ships, it’s a go-kart track. Carnival has Bolt, the first roller coaster at sea, now found on three of its ships. Royal Caribbean’s six Oasis Class ships have the AquaTheater, where high-divers perform aerial acrobatics above the deepest pool on a cruise ship.

In 2018, I traveled on the Norwegian Breakaway. Did I need a go-kart track at sea? Not really, but I still got a kick out of taking a few spins around the track.

But with so many options, can you even take advantage of everything a megaship has to offer on a seven-day cruise? Probably not, says Sandi Valente, president of Valente Vacations, based in Fort Lauderdale, Florida. “Don’t plan on doing everything on your first sailing,” says Valente. “By trying to find all the bells and whistles you may miss something amazing.”

Here’s your guide to navigating a mega cruise ship:

• Watch ship tours on YouTube. “On the surface, the ship may seem gargantuan,” says Matt Hochberg of the Royal Caribbean Blog (not an official blog of the cruise line, it should be noted). “When you see a walk-through video of a ship, it removes any trepidation and makes it feel more manageable.” Adds Judith Gaines, a regular cruise vacationer from West Bloomfield, Michigan: “There’s a video for every single cruise ship out there. You can see every style of suite. There’s a vast amount of info and preplanning tools.”

• Make a plan. “Look over the deck plan online and isolate the areas you are interested in to maximize your time onboard,” says Valente. This also applies to cruisers with experience on smaller or older ships. “Someone who hasn’t cruised for 15 or 20 years doesn’t realize that it’s not just the size but also the layout of the ships that has changed.”

• Choose your cabin location carefully, says Colleen McDaniel, editor-in-chief of the website Cruise Critic. You don’t want to return to your cabin only to realize it’s directly above a pulsing club or below a noisy gym or running track. “Your cabin will be your place to recharge,” McDaniel says.

• Make reservations well in advance. Theaters on megaships are large, but not large enough to host all guests unless shows are repeated three or four times. So get your seats saved. If your plans change, you can always cancel. The same goes for dining. Royal Caribbean’s Symphony of the Seas, currently the fourth largest cruise ship, boasts 20 different dining options. But if you want to dine at Hooked Seafood or the steakhouse Chops Grill, these venues seat just 80 and 90 people, respectively, while the ship carries over 5,500 passengers. The vast majority of guests will not have the option to eat there without a reservation. “Many popular alternative dining venues sell out far in advance, as do many shore excursions,” says Tom Baker, Houston-based travel adviser at CruiseCenter. “A good travel adviser will impart this to ensure all is done within the proper time frame to avoid disappointment down the line.”

• Consider upgrading to a suite enclave, which is a dedicated, more secluded area on some ships. They cost about double that of a regular cabin but are quieter and may be child-free. McDaniel cites as examples MSC’s Yacht Club and Norwegian’s Haven. “They come with VIP treatments like exclusive dining venues, pools and lounges open only to those staying in those areas.”

• Download the cruise line app to your mobile device before boarding. Depending on the line, this may allow you to speed your check-in, make reservations for dining and shore excursions, view deck plans and chat with other members of your party. On Princess Cruises, I loved how the app unlocked my cabin door as I approached, saving me from reaching for a key card when my hands were full with coffee cups.

• Skip the ship buffet on embarkation day. “Everyone heads straight there,” Valente says. “Check your cruise planner to see what other options are available.”

• If you like quiet areas, spend an hour on embarkation day scouting them out. “I am an old-school cruiser who absolutely loves a good wraparound promenade deck,” says Margo Nirel, vacation and cruise consultant for Expedia Cruises. “Just walking a lap or two around the ship relaxes me and gets me away from the throngs enough to recharge.” Nightclubs (when not in use), libraries and fee-added thermal spa areas are other places to look for solitude and quiet.

• Although ship Wi-Fi makes communication easier for traveling companions, identifying a central meeting point will make it easier to gather for meals, shore excursions and other activities.

• Go where the people aren’t. “On MSC Seaside I used the gym in the late afternoon, and it wasn’t busy,” says cruiser Maribeth Mellin. “We used the spa when everyone got off in the ports and we had it almost to ourselves.” Dining early or late allows you to check out normally busy areas of the ship when most guests are eating.

• If there’s a show you want to see that is sold out when you board, arrive at least 30 minutes prior to showtime. “People make a reservation and then decide to do something else,” says Hochberg. “There are always standby lines.”