A cruise ship or cruise liner is a passenger ship used for pleasure voyages, where the voyage itself and the ship's amenities are part of the experience. Cruising has become a major part of the tourism industry, with millions of passengers each year. The industry's rapid growth has seen nine or more newly built ships catering to a North American clientele added every year since 2001, as well as others servicing European clientele. Smaller markets such as the Asia-Pacific region are generally serviced by older tonnage displaced by new ships introduced into the high growth areas.
Cruise ships operate mostly on routes that return passengers to their originating port. In contrast, ocean liners do "line voyages" and typically transport passengers from one point to another, rather than on round trips. Some liners also engage in longer trips which may not lead back to the same port for many months.
Traditionally, an ocean liner will be built to a higher standard than a cruise ship, including stronger plating to withstand ocean voyages, most commonly crossing the North Atlantic. The only traditional ocean liners in operation, as of August 2008, are Queen Mary 2 and Queen Elizabeth II (to be retired in November 2008), both part of the Cunard fleet. The liners RMS Queen Mary and SS United States are also extant, with long-standing plans to return the latter to service, although this appears increasingly unlikely given its age and condition.
The practice of cruising grew gradually out of the transatlantic crossing tradition, which never took less than four days. In the competition for passengers, ocean liners added many luxuries — the Titanic being the most famous example — such as fine dining and well-appointed staterooms.
In the late 19th century, Albert Ballin, director of the Hamburg-America Line, was the first to send his transatlantic ships out on long southern cruises during the worst of the winter season of the North Atlantic. Other companies followed suit. Some of them built specialized ships designed for easy transformation between summer crossings and winter cruising.
The 1970s television show The Love Boat, featuring Princess Cruises' since-sold ship Pacific Princess, did much to raise awareness of cruises as a vacation option for ordinary people in the United States. Initially this growth was centered around the Caribbean, Alaska and Mexico, but now encompasses all areas of the globe. Today, several hundred cruise ships, some carrying over 3,000 passengers and measuring over 120,000 gross tons, ply routes worldwide. And even larger vessels are on the horizon. Plans are set for at least two cruise ships that will be 220,000 gross tons and hold 5,400 passengers each. For certain destinations such as the Arctic and Antarctica, cruise ships are very nearly the only way to visit.
As with any vessel, adequate provisioning is crucial, especially on a cruise ship serving several thousand meals at each seating. For example, passengers and crew on the Royal Caribbean International ship Mariner of the Seas consume 20,000 pounds (9,000 kg) of beef, 28,000 eggs, 8,000 gallons (30,000 L) of ice cream, and 18,000 slices of pizza in a week.
Many older cruise ships have had multiple owners. Since each cruise line has its own livery and often a naming theme (for instance, ships of the Holland America Line have names ending in "-dam", e.g. MS Statendam, and Royal Caribbean's ships' names all end with "of the Seas", e.g. MS Freedom of the Seas), it is usual for the transfer of ownership to entail a refitting and a name change. Some ships have had a dozen or more identities.
Cruise ships and former liners often find employment in applications other than those for which they were built. A shortage of hotel accommodation for the 2004 Summer Olympics led to a plan to moor a number of cruise ships in Athens to provide tourist accommodation. On September 1, 2005, FEMA contracted three Carnival Cruise Lines vessels to house Hurricane Katrina evacuees.
The Caribbean cruising industry is a large and growing market, and currently the most popular. Cruising has grown from “an estimated 900,850 passengers in 1983 to 2.3 million passengers in 1993”. Cruise lines operating in the Caribbean include Royal Caribbean International, Princess Cruises, Carnival Cruise Line, Celebrity Cruises, Disney Cruise Line, Holland America, P&O, Cunard, and Norwegian Cruise Line. There are also smaller cruise lines that cater to a more intimate feeling among their guests. The three largest cruise operators are Carnival Corporation, Royal Caribbean International, and Star Cruises/Norwegian Cruise Lines.
Many of the American cruise lines in the Caribbean depart from ports in the United States, “nearly one-third of the cruises sailed out of Miami”. Other cruise ships depart from Fort Lauderdale ("Port Everglades"),Port Canaveral, New York, Tampa, Galveston, and San Juan. Many UK cruise lines base their ships out of Barbados for the Caribbean season, operating direct charter flights out of the UK and avoiding the sometimes lengthy delays at US immigration.
Cruises sailing in the Caribbean travel on itineraries depending on the port of departure and the length of the cruise. The busiest port of call is the Bahamas with “1.8 million cruise-ship arrivals in 1994”. This is because its short distance from Florida is very convenient for both short and long cruises. The next most popular ports of call were “the US Virgin Islands (1.2 million), St. Maarten (718,553), Puerto Rico (680,195), the Cayman Islands (599,387), and Jamaica (595,036)”. Other ports of call include: Belize City, Costa Maya, Cozumel, Antigua, Aruba, Grand Turk and Key West. St Thomas in the US Virgin Islands is particularly popular with US passengers because they get a second Duty Free allowance to use on goods purchased there.
Many cruise lines also have stops at their own "private islands", more truthfully, a private section of a Caribbean island. These private resorts are reserved exclusively for passengers of the respective cruise line using the location, and frequently offer features such as an Aqua Park, kayaking, snorkeling, parasailing, music, and private reservable cabanas.
A large number of cruise ships have been built by other shipyards, but no other individual yard has reached the large numbers of built ships achieved by the three above. A handful of old ocean liners also remain in service as cruise ships. Despite the dominance of United States-based cruise ship operators and American clients in the industry, only one ship built in the United States, the , is still sailing.