The biggest challenge the cruise industry faces is convincing more people to take cruises, Carnival Corp. CEO Arnold Donald said in an interview with Business Insider.

The total number of cabins on all of the world's cruise ships amounts to less than 2% of the world's hotel rooms, Donald said. In 2017, the total number of global cruise passengers was 26.6 million. In 2014, an average of 4.8 million people stayed in US hotels each night.

"The cruise industry is tiny," Donald said.

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A limited amount of ship-building capacity puts a ceiling on how much the cruise industry can grow each year, but Donald hopes to create more demand than Carnival can meet.

"The challenge is creating demand in excess of supply to be able to narrow the gap," Donald said.

Carnival relies on a variety of channels to reach potential customers, including social-media posts from passengers, travel agents, traditional advertising, cold calling, and TV shows it has created for major networks, such as ABC's "Ocean Treks" and NBC's "The Voyager."

The ultimate goal, according to Donald, is to have every potential customer encounter a "positive feeling" about the cruise industry multiple times each day.

"We're always looking for how to get the story out," he said.

Have you worked on a cruise ship? Do you have a story to share? Email this reporter at mmatousek@businessinsider.com.