Two of Royal Caribbean's newest ships both promise big thrills and nonstop memory-making. But from vibe to voyage length, Utopia of the Seas and Icon of the Seas offer different vacation experiences.

A photo taken on May 15, 2016, shows the Harmony of the Seas cruise ship as it sails from the STX Saint-Nazaire shipyard, western France out to sea.

If you're trying to choose between Utopia of the Seas and Icon of the Seas for your next Royal Caribbean cruise, good luck. These two megaships are the line's newest, biggest floating playgrounds.