The cruise industry needs to do a better job of changing the public's negative perception of its biggest ships, key executives said Tuesday.

Last fall, Royal Caribbean Cruises launched the world's largest passengership — the 6,870-berth Symphony of the Seas (built 2018) — and unveiled plans to build an even bigger ship to round out the Oasis class of world's largest cruise vessels.

Meanwhile, Carnival Corp has the 6,600-berth AidaNova (built 2018) and Norwegian Cruise Line has 4,200-berth Norwegian Bliss (built 2018).

"It's a still a more efficient way to move 5,000 passengers than it is to move 5,000 passengers via 747 airplanes," Norwegian chief executive Frank del Rio said during an industry panel at Seatrade Cruise Global in Miami Beach.

Royal Caribbean chief executive Richard Fain said the public view on these ships as monsters to the environment needs to be corrected.

"The larger the ship oftentimes has a dramatically lesser carbon footprint," he said.

Carnival chief executive Arnold Donald agreed, saying the industry is working on showing people that it is making strides in being more environmentally friendly.

"The reality is ... we reduced our fuel consumption by 33% since 2007," he said.

"It's also imperative for our business that the marine environment be pristine."

MSC Cruises chief executive Pierfrancesco Vago said the cruise industry is actually setting an example for all of maritime shipping on becoming less harmful to Mother Nature.

"The cruise industry is doing an excellent job leading the way," he said.