

During long-haul flights (which is the case for trans-atlantic flights), planes average about 100g CO2 per passenger-kilometer.
Ocean-worthy passenger ships are frequently in excess of 200g CO2 per passenger-kilometer for basic passenger transport vessels. Cruise ships are much worse even, frequently emitting >400g CO2 per passenger-kilometer.
So, how would boats be better for crossing the Atlantic?
Oh sure I’m “reading airline propaganda”.
If you want to claim any counter-argument is some evil company’s propaganda, then please go back to your echo chamber and I am no longer interested in discussing with you. Goodbye.