As part of its vessel sanitation program, the Centers for Disease Control and Prevention (CDC) monitors the sanitation of all cruise vessels carrying more than 13 passengers having foreign itineraries with ports of call in the U.S.

Random inspections verify that ships are maintaining a healthy and safe environment on board. Inspectors use a score of one to 100, with any score below 85 considered failing. Current CDC cruise ship scores are posted online along with details of the overall CDC Vessel Sanitation Program (VSP).

During the surprise visits, the ship and crew will undergo inspections of the galley, drinking water treatment facilities, garbage handling areas, swimming pools and other water recreation areas, among other things. The CDC cruise ship score is based on a 300-page manual filled with mind-boggling details. Did you know, for instance, that self-serve scooped ice cream should be served in a shallow pan "no deeper than 4 inches and no longer than 12 inches"?

One wrong-sized serving pan or one box of crackers stored on a pantry floor rather than the required six inches above the floor can cause a deduction in the ship's score. Scores of 100 are a major accomplishment. The CDC highlights that achievement with a separate list of ships that have earned the top score.