Operators of cruise ships are known as cruise lines. Cruise lines have a dual character; they are partly in the transportation business, and partly in the leisure entertainment business, a duality that carries down into the ships themselves, which have both a crew headed by the ship's captain, and a hospitality staff headed by the equivalent of a hotel manager. Among cruise lines, some are direct descendants of the traditional passenger shipping lines (such as Cunard), while others were founded from the 1960s specifically for cruising.
Historically, the cruise ship business has been volatile. The ships are large capital investments with high operating costs. A persistent decrease in bookings can put a company in financial jeopardy. Cruise lines have sold, renovated, or renamed their ships to keep up with travel trends. The cruise lines operate their ships virtually 24 hours a day, seven days a week, 52 weeks a year. A ship which is out of service for routine maintenance means the loss of tens of millions of dollars. If the maintenance is unscheduled, it can result, potentially, in thousands of dissatisfied customers.