Carnival cruises that visit islands in the French West Indies (Guadeloupe, Martinique, Saint Martin and Saint Barts) require a valid passport regardless of departure port. Children under the age of 16 who are citizens of the U.S. or Canada are exempt from the passport requirement for land and sea border crossings.

For U.S. citizens on "Closed-Loop" cruises (those starting and ending at the same U.S. port), children under 16 do not strictly need a passport; they can travel with an original or certified copy of their government-issued birth certificate. However, for all other international sailings or flights, a valid passport is mandatory. In 2026, Carnival and travel experts strongly recommend that all children carry a passport anyway. If a medical emergency occurs or the ship is diverted to a foreign port not on the original itinerary, a child without a passport would be legally unable to fly home. Additionally, some specific destinations like Martinique or Guadeloupe require a passport regardless of the cruise type. Relying on a birth certificate is a "budget" option, but a passport is the only way to ensure 100% travel flexibility and safety for a child in the event of an unforeseen travel disruption.