Carnival said the guarantee is unprecedented and is available now fleet-wide.

Guests who find the same tour offered by another operator at a lower price than their booked excursion (before or during their cruise) can complete a claim form to receive 110% of the difference in the form of a shipboard credit.

Claims are typically processed within 24 to 48 hours, Carnival said.

Mico Cascais, Carnival’s vice president of tour operations, said the guarantee was developed based on research findings that passengers, particularly first-time cruisers, are concerned about whether they are getting the best deal.

Companies that represent excursion operators independent of the cruise lines say they can offer better prices because they work on lower markups. In many cases, passengers can buy excursions directly from excursion operators.

Carnival said that by booking through the cruise line, passengers get tickets delivered to their staterooms and “an assurance that they will receive a refund or the excursion time will be adjusted as needed based on weather or other issues affecting a ship’s scheduled port of call visit.”

To file a claim, Carnival said passengers should provide the name of the competitor offering the comparable tour, the excursion name, where the tour was advertised, the duration, price and any included items such as lunch, drinks, transportation and admission fees.