More than half of those who've never taken a cruise would like to do so, according to a 2006 survey by the Cruise Lines International Association.
But if you've never cruised before, the concept might sound intimidating. How do you book? How do you dress for dinner? How much do you tip?
Here are five things first-time cruisers need to know.
1. Must I use a travel agent to book a cruise?
Every cruise line has a website. You can easily book your own trip.
But which cruise is right for you? Do you like partying in discos and bars, or would you prefer Tommy Dorsey-style music in the cocktail lounge? For shore excursions, are you up for kayaking, or do you want the trolley tour? Do your kids need a baby-sitter, organized arts and sports activities, or a teen lounge?
You can research and compare what each ship offers, or get advice from Web sites like CruiseCritic.com or TripAdvisor.com.
But it costs nothing extra to consult a travel agent, ''and you've got a professional who may actually have seen or been on the ship doing the work for you,'' said Bob Sharak, the cruise association's vice president for marketing.
2. Do I have to eat in the formal dining room with strangers and dress for dinner?
Most ships have various dining options: buffets, cafés, specialty restaurants and formal dining rooms. Many ships offer ''dress casual'' nights in the formal dining rooms. But even formal dress nights don't necessarily mean tuxedos and gowns; a suit or dress will do. And some folks dress casually even on formal nights.
Some cruise lines let you sit where you want in the dining room. If not, chances are you'll have fun meeting other people at your table.
The dining room can also help you avoid loading your plate repeatedly at the buffet. Portions are controlled (although you can always request more than one entree or dessert); and some menus highlight low-fat or low-calorie options.
3. What should I pack?
Bring flip-flops or other slip-on shoes, and a robe or cover-up for walking from the pool to your cabin.
Pack for the weather. A New York-Caribbean trip in winter means a few cold days at sea. Alaska in August? Bring rain gear.
Some ships have self-serve washing machines and dryers, some don't. Sending dirty clothes out to the ship's laundry can be costly. So bring enough clothing for your trip, or find a coin-op laundry in port. Your stateroom bathroom may have a pullout clothesline for drying swimsuits or hand-washed items.
If you want a clock by your bedside, bring one. Not all staterooms have them (though you can always arrange a wake-up call).
The stateroom bathroom will have shampoo and soap, but not necessarily free moisturizer and conditioner, like you'd expect from a hotel.
4. Does the price include everything?
Cruise prices include the room, food and some beverages. Free drinks might include coffee, tea, iced tea, lemonade and, with breakfast, juice.
Luxury cruise lines don't charge extra for wine or liquor. On many other lines, you can't even get soda for free, but you can buy beverage packages with unlimited soda ($6 a day is typical).
You could spend a lot on alcohol, casinos, spas, Internet access, video games and shopping.
If you're on a budget, stick to free activities -- pool, gym, shows and, in port, a stroll through town or the beach instead of that pricey helicopter tour.
If you want shore excursions, you'll find vendors offering tours in each port. They may charge less than the cruise line charges for similar outings.
But if you have your heart set on a certain activity, book in advance through the cruise line. Popular tours will sell out.
''If you're dying to do a glacier sightseeing trip in Alaska, you've booked it in advance and it's taken care of,'' said Sharak. ``Or if your tour bus gets a flat tire and is tardy coming back to the ship, if you've booked it through the cruise line, that ship is not going to leave without you.''
5. How much and whom do I tip?
Some luxury lines forbid tipping. Other cruise lines recommend certain amounts. Some offer prepaid gratuity options or levy a service charge for dining room staff and the person who cleans your room. A typical tip for stateroom attendants is $3.50 a day; dining room staff tips run $5-$10 per day, with that amount shared by your waiter, wine steward and maitre d'.
With prepayments, you're charged a gratuity for each person in your party, for each day of the cruise. So even if your kids never eat in the formal dining room, prepaid tips will go to the servers on their behalf. You might be better off deciding on tips near the end of your cruise, in case it makes more sense to tip a buffet worker who delighted your children each night at dinner with a magic trick.