They can do it in 5 days, but most of the time they want you on there longer. It means they can both conserve fuel, and have you spending money for longer once

They can do it in 5 days, but most of the time they want you on there longer. It means they can both conserve fuel, and have you spending money for longer once you're captive. Source: I worked on cruise ships for a couple of years. FWIW the crossing I did with Holland America took 6 days.