Last week, Carnival announced it was conducting "a comprehensive review" of all 23 of its ships after the fire that crippled Triumph.

Carnival President and CEO Gerry Cahill said the investigation will focus on the prevention, detection and suppression of fires, engine room redundancies and what additional hotel facilities might be provided and might run off the emergency generators.

"We are now focused on the lessons we can learn from the incident and also what additional operational redundancies might be available," Cahill said last week.

Another ship, the Carnival Splendor, had a fire in 2010 due to "a catastrophic failure of a diesel generator," he said.

Not doomed

Despite all the recent problems, Donahue doesn't see any long-term negative effects for Carnival or its competitors.

"I don't necessarily see (last) week's events, or even combined with the Triumph event, as casting a pall on the cruise industry," he said, noting that several colleagues and friends who have recently gone on cruises, including on Carnival, enjoyed their vacations.

"People generally accept that complex pieces of equipment can encounter challenges. That's not the hurdle. I don't think anybody considering the cruise would be unforgiving of an unforeseen event, because those types of events occur with complex systems. People are far less forgiving (when) communications around the events seem to be lacking."