Voyager-class cruise ship: 12.8-passenger-miles per gallon Boeing 747-400: 91 passenger-miles per gallon Of course passenger aircraft are tightly packed and c

Voyager-class cruise ship: 12.8-passenger-miles per gallon Boeing 747-400: 91 passenger-miles per gallon Of course passenger aircraft are tightly packed and cruise ships have large cabins, swimming pools, etc. Both numbers from https://en.wikipedia.org/wiki/Energy_efficiency_in_transport https://en.wikipedia.org/wiki/Energy_efficiency_in_transport