Norwegian Cruise Lines non-refundable service charge.

 Not quite a gratuity but not part of the fare either, it pays for … what? it is unclear, even after talking with its inventor.

Norwegian Cruise Line made the charge mandatory this summer with the launch of its Hawaii cruises on Pride of Aloha — unfortunate timing,  and plans to add it fleetwide in summer 2005, when it will be sailing 13 vessels.

Adults are charged $10 per day, children 3 to 12 are charged $5, and younger children are free.

 Beyond that, Pride of Aloha passengers are not obliged to tip for "service that is generally rendered to all guests," the company said.

Although Norwegian has assessed a service charge for several years — "purely for people's convenience," said Chief Executive Colin Veitch — what's new is making it nonrefundable.