Updated October 18, 2017
An inaugural cruise is typically the first time a cruise ship sails with paying passengers. Before that sailing, there might be sailings for special invited guests and members of the media. A ship may also have "mini" inaugural cruises as it moves from one part of the globe to another for the first time. For example, a ship might have a North American inaugural cruise the first time it sails there, or an inaugural Alaska cruise. In those cases, the ship might not even be new; it might only be new to the region.
Passengers on inaugural sailings of new ships are often treated to a bit of fanfare as the ship sails away or as it arrives in each new port. The cruise line might also provide booking incentives and even extra goodies onboard for cruisers willing to be the first paying passengers to try out a ship or itinerary.
The downside to an inaugural cruise could be a crew slightly unfamiliar with the operations of the new ship. Cruise lines attempt to minimize that by staffing new ships with experienced crew members from other similar ships within the line and by providing extra training. Some ships are not 100 percent ready for their maiden voyage, and have workers still onboard, roped-off areas under construction or attractions not ready for passengers. In the most extreme cases, some inaugural cruises have been canceled with the first sailing date pushed back if the ship won't be ready in time.