With some cruises towering almost 240 feet above the water line, the engineering marvels have some tricks up their sleeves to maneuver through tight spaces, such as underneath bridges.
Last year, Icon of the Seas, the world's largest cruise ship had to navigate under Denmark's Great Belt Bridge en route from Finland to Spain.
While successful, the operation took a lot of planning and coordination between the crew, ranging from those working in meteorology to operations.