Cruise ships offer many engaging opportunities for real-world math adventures. These large, floating cities use resources with numbers into the thousands place. Young mathematicians are asked to calculate numerical information relevant to the amount of food, water and waste containment. The ending question is an open-ended extension that invites learners to create a cruise ship of their own.  Note: A lesson plan is not attached, but the information on the pages contains thorough directions and is ready to be used in the classroom.