There might be a nuance missing, in that if you compare a plane journey vs a cruise you are of course not comparing like to like if you only consider 'CO2 per p

There might be a nuance missing, in that if you compare a plane journey vs a cruise you are of course not comparing like to like if you only consider 'CO2 per passenger mile' as aeroplanes are used to travel further than a cruise ship. I don't know the mileage that they actually cover on a cruise, but at 20kts they could cover 480 miles in 24 hours and bearing in mind that they are spending time in port it will be less than that. Lets estimate 300 miles per day, so a 2 week cruise could rack up ~4200 sea miles. => 1806 Kg of CO2 If I flew from Heathrow to Antigua for those 2 weeks, that would be ~8000 air miles. => 2056 Kg of CO2