Carnival Cruise Lines 800/327-9501
Has 3-, 4-, and 6-day cruises to Key West and the Caribbean as well as 7- and 9-day excursions that include stops in Mexico, Jamaica, and the Cayman Islands. There's a smoke-free ship called the Paradise. Cruises usually depart from Miami Friday through Monday. Prices range from $400 to $3,000 (lower rates are usually available, depending on season), not including port charges, which can be as high as $200 per person.
Cunard 800/528-627
Caters to an older, sophisticated crowd. If you're looking for Internet cafes and ice-skating rinks, Cunard isn't for you. This line's Miami ships include the legendary throwback from the halcyon days of the mighty luxe ocean liner Queen Elizabeth II , as well as the Queen Mary II. Itineraries are usually at least 10 days long, though there are some that last 6 days, such as the jazz, fine arts, and big-band cruises. Prices start at $3,300 per person.
Norwegian Cruise Line 800/327-7030
Has four ships based in Miami during the winter months and usually one in the summer. NCL is known for having the most flexible dining setup at sea, with open seating and casual dress codes. A mixture of young and older crowds can be found on their ships. Ships go to Key West, the Bahamas, and the Western Caribbean. Its shortest cruises are 3 days; the longest -- from Miami to France -- is 15 days. Rates range from $42 per person for an inside cabin on the shortest cruises to $4,500 per person for the very best cabin on the transcontinental journey.
Royal Caribbean International 800/327-6700
One of the premier lines in Miami, has about half a dozen ships departing Miami at any given time. The Port of Miami actually had to renovate three cruise terminals in 1999 -- at a price of $60 million -- to accommodate Royal Caribbean's 142,000-ton ship Voyager of the Seas , which boasts an ice-skating rink and a rock-climbing wall, among other theme-park-like diversions. Mariner of the Seas, Navigator of the Seas, Explorer of the Seas , and Adventure of the Seas are the line's four other theme parks at sea, totaling to five Voyager -class ships also featuring extreme sports and an assortment of high-tech activities. As a result, RCI caters to a young and old(er), active crowd as well as families with children. The line mostly offers Caribbean cruises and some Bahamas destinations. The Legend of the Seas and the Splendor of the Seas offer 3- and 4-night Bahamas trips for as low as $100 per person, per day, to as high as $7,500 per person for an 11-night cruise through the Caribbean.