Setting sail is simply the most convenient and economical way for a family to see the world together. You'll visit multiple destinations in a single voyage, and today's cruise ships are chock-full of family-friendly features (nearly all of which are included in your fare).

There's the exciting stuff: the enormous, twisting waterslides and colorful waterparks aboard Carnival's "Fun Ships®;" the rock-climbing walls, surfing simulators, and zip lines found aboard most vessels in Royal Caribbean's innovative fleet; opportunities to mingle with your favorite film and television characters on a Norwegian or a Disney Cruise Line voyage; and so much more.

Then there's the practical (but essential) stuff that parents and grandparents depend on so that they can enjoy themselves without worry: award-winning youth programs (supervised by highly qualified counselors) that entertain and educate young passengers both at sea and in port; a broad selection of dining options featuring healthy choices and flexible mealtimes; and adults-only areas (including tranquil solariums and intimate specialty restaurants) that respect a grown-up's need for periodic privacy.

Nearly all of today's top-brand cruise lines cater to families, but four lines in particular are famous for making it a priority: Carnival Cruise Lines, Disney Cruise Line, Norwegian Cruise Line, and Royal Caribbean International.

Among family-friendly cruise lines, Carnival offers the most choice: 25 ships (at time of writing) and hundreds of unique itineraries ranging in length from three to fourteen nights.

Its marine-themed youth program, Camp Ocean (formerly Camp Carnival), is free and available throughout each day; after-hours programming (a.k.a. "Night Owls," which runs from 10:00 PM through 1:00 AM) is also available for a fee. Young children are divided into three age-appropriate groups - "Penguins" (ages 2 to 5), "Stingrays" (ages 6 to 8), and "Sharks" (ages 9 to 11) - and there are additional activities and allocated spaces for passengers ages 12 to 14 (Circle C) and passengers ages 15 to 17 (Club O2). Highlights include shipboard scavenger hunts, video games, group sports, dance/pool parties, and special teens-only excursions.

And the cruise line's youth programming is only the beginning. Every Carnival vessel is jam-packed with fun-filled options including the largest collection of waterparks at sea; SkyCourse (an aerial ropes course); SkyRide (aerial cycling); SportsSquare (mini-golf, a basketball/volleyball court, and more); a three-story IMAX® Theatre (exclusive to Carnival Vista); Hasbro™, The Game Show (legendary board games, brought to life); and so much more. Carnival also offers several of cruising's most family-friendly stateroom configurations (e.g. Family Harbor Staterooms, which connect to a dedicated Family Harbor Lounge) plus dozens of different dining options including a Seuss-themed "Green Eggs & Ham" Breakfast, Guy Fieri's Burger Joint, and fresh Mexican favorites at the BlueIguana Cantina.

Synonymous with family entertainment for close to a century, Disney first began offering cruises back in 1998, and since that time its cruise ships have consistently ranked among the world's best.

Four Disney vessels - Disney Dream, Disney Fantasy, Disney Magic, and Disney Wonder - set sail for the Bahamas, the Caribbean, and other popular destinations. Every voyage kicks off with a special Sail-Away Celebration (an exuberant deck party starring classic Disney characters like Mickey, Minnie, and Donald), and most Bahamian and Caribbean itineraries include a visit to Castaway Cay, Disney's private island.

The cruise line's youth clubs are, as you'd expect, top-notch: there's the Oceaneer Club and the Oceaneer Lab for guests ages 3 to 12 (themed play spaces include Andy's Room from Toy Story and Tinkerbell's Pixie Hollow); Edge (a high-tech hangout for 'tweens); and Vibe (a teens-only retreat replete with its own media room, dance floor, and sundeck). Additional shipboard highlights include AquaDuck (Disney's thrilling waterslide); the Animator's Palate (an innovative dinner show for passengers of all ages); and unforgettable meet-and-greets with Marvel's® Avengers, Pixar pals like The Incredibles, and select heroes and villains from the Star Wars films (you'll even find a full-sized replica of the Millennium Falcon's cockpit aboard Disney Dream). Adults-only offerings include Quiet Cove Pool; Senses Spa & Salon; The District (an entire "neighborhood" of age-restricted bars/clubs, exclusively available aboard Disney Dream); and kids-free dining at Palo and Remy (Northern Italian and gourmet French, respectively).

It only makes sense that the folks who invented "Freestyle Cruising" - the freedom to dine, dress, and play as you please while at sea - would be such a good fit with families.

All told, you and your crew have 16 exciting Norwegian ships to choose from, and the cruise line's newest - Norwegian Epic, Norwegian Breakaway, Norwegian Escape, and others - are among the biggest and boldest at sea. Shipboard highlights include Norwegian's awesome Aqua Park (featuring the 250-foot Epic Plunge, cruising's first-ever bowl slide); Bliss Ultra Lounge (home to cruising's first-ever bowling alley); 678 Ocean Place (three entire decks' worth of bars, dining, gaming, and more); and Broadway-caliber productions of popular favorites like Cirque Dreams®, Jersey Boys, and Rock of Ages. Few cruise lines offer passengers more restaurants per ship (up to a dozen of which are included in your fare; children are also welcome in Norwegian's specialty venues) and you'll find Family Balcony Staterooms, as well as a number of interconnecting cabins, available aboard every Norwegian vessel. There are also dedicated spaces (e.g. Posh, Vibe, and Spice H2O) that are exclusively reserved for adults.

Norwegian's youth program, Splash Academy, is specifically designed for children between the ages of 6 months and 12 years; activities are based on age groupings (e.g. sensory play for "Guppies" under three years of age). Highlights, which vary from ship to ship, may include a circus school and a modest cinema. There's also a hangout that's exclusively for teens (Entourage, which converts into a teens-only nightclub after dark).

Royal Caribbean's mega-ships are, quite literally, floating metropolises. Seven of the world's ten biggest cruise ships are Royal Caribbean ships (including six of the top seven), and select vessels (e.g. Harmony of the Seas , Allure of the Seas) are capable of comfortably accommodating well over 6,000 guests in a single voyage. And all that size means an unbeatable number of choices.

Royal Caribbean always delivers the "wow" factor (no other cruise line can lay claim to a greater number of "firsts"). Deck-defying innovations include its now-famous rock-climbing walls and ice-skating rinks; the ever-popular FlowRider®; up to seven unique "neighborhoods" per ship (including Boardwalk®, Central Park®, and Entertainment Place); The DreamWorks® Experience (meals, movies, and more with all of your favorite characters from Shrek, Kung Fu Panda, and other blockbusters); and the H2O Zone^SM Water Park. You'll also enjoy a wide range of family-friendly accommodations including the Royal Family Suite (room for up to eight guests) and the Family Ocean View Stateroom (room for up to six). Dining options range from casual (e.g. Johnny Rockets®, Sorrento's Pizza) to upscale and multi-course (e.g. Chef's Table, 150 Central Park).

Adventure Ocean®, Royal Caribbean's award-winning youth program, boasts some of the largest dedicated facilities found at sea (close to 30,000 sq. ft. aboard select vessels). Children are grouped by age - Aquanauts (ages 3 to 5), Explorers (ages 6 to 8), etc. - and there are also activities for guests ages 6 months to 36 months (Royal Tots and Royal Babies; parental participation is required). Teens-only spaces include Fuel (a nightclub) and The Living Room (a coffeehouse-style retreat).