Carnival Corp., trying to dispel consumer concerns about the cruise industry, is inviting the public to design its next marketing campaign, including people who’ve never set foot on a ocean liner.

Among the issues Carnival hopes to address: “I don’t want to be on a buffet line with 3,000 people. I don’t want to be confined. I don’t want to get seasick. It’s only for old people,” Arnold Donald, chief executive officer of the world’s largest cruise company, said Tuesday on a call with reporters.