In 2012, London-based couple Ben Hewitt and David McDonald were invited to a friends wedding they feared was going to be awful. The ceremony was taking place on a cruise ship and the pair, then 27 and 22, dreaded all the cruising clichs stale buffets and overcrowded swimming pools. But they ended up loving the experience so much Its like a resort at sea, said McDonald that theyve taken 29 more cruises, averaging three or four a year.

Theres been a huge change, even in the eight years weve been doing this, where cruise lines are actively aiming towards millennials and young people, said Hewitt, now 35. Seems like that was working. When Hewitt and McDonald started documenting their cruises on YouTube three years ago, the average age of their audience was 45 now, its 35.

A report from the Cruise Lines International Association (CLIA) in December found that 71% of millennials had a more positive attitude about cruising than two years earlier. And research firm Mintel found last spring that more than a third of people interested in taking a cruise over the next five years were between 16 and 34 years old .

Overall, 17.8 million people went on a cruise in 2009. In 2019, its estimated that the industry surpassed 30 million voyagers for the first time.

Yet its increasingly apparent there are some serious downsides to this vacation vehicle. As everyone has just been reminded, cruise ships can be breeding grounds for disease, like the coronavirus that stranded people aboard the Diamond Princess in Japan and the Princess Cruises ship off the coast of California.

Most cruises dont lead to illness and quarantines, of course. But the ships still leave long and lasting wakes of ecological damage. And that could be an issue for all those future millennial and Gen Z passengers, the two generations most concerned about the environmental impact of their actions.