Cruise ship Carnival Valor docked in Marseille.
Carnival can charge passengers a "fuel supplement" fee of up to $9 per day without prior notice if the price of crude oil rises above $70 per barrel, according to the cruise line's contract of carriage.
  • Carnival's CEO said a fuel surcharge is "certainly not off the table" during an earnings call.
  • He said it's not something the company is planning on doing imminently, however. 
  • The cruise line can charge up to $9 per person per day without prior notice. 

If you think filling up your car's tank is expensive, imagine the gas bill for 80-plus cruise ships.