Yes, many will take planes and trains and cars, any of which will still pollute less than cruise ships.
There is no downside to banning them and using sail ships (aside from a potential loss of revenue).
Sailing ships have unreliable schedules, for one.
This sentence made me think... how many people are toiling hard under the promise that, when they amass enough wealth and eventually retire, then they'll have time to jump on cruise ships and see the world? Isn't this the tail end of the American dream? No surprise then that there isn't a widespread consensus to kill the cruise shipping industry - as you have people burning the best years of their life chasing a carrot, only for you to propose to take the carrot away.
At the very least, the cruise ship operators should be made to internalize the entire environmental cost of their pollution. The best way to do that would be through taxing bunker fuel, but that may cause mayhem with the entire shipping industry, so I'd initially be fine with just a large and very much unfair tax on cruise operators. Not enough to take away the carrot, but enough to make it appropriately expensive, relative to the environmental costs. Now is probably the best time for that - the companies are devastated by COVID and won't have money to bribe^H^H^H^H^Hlobby against such measures.
It's quite hard to tax them. They sail under Panama flags in international waters and are registered in some country most people haven't heard of. They can only be taxed while at anchor in a port under some jurisdiction. They'll happily refuel in Jamaica, Cuba or Haiti if fuel is taxed in the US. We've seen that in Europe with truckers and fuel taxes in some jurisdictions.
My stand is, burning dirty oil for people's enjoyment to the detriment of the oceans and the air is [insert bad words].
I said, use sailboats for leisure tourism. Plenty of fun.
At this rate, we'll fuck up the planet enough that governments will take the power in their hands and everyone will be forced to help with the cleanup.
If we don't do something now, out of our own volition, we're all going to end up with much more authoritarian governments and limits on individual freedoms. It's either that or civil wars. No way around it.