Cruise ships can be surprisingly scary because they combine isolation, the vastness of the ocean, and a sense of vulnerability. Out in the middle of the sea, far from land, passengers can feel cut off from the outside world, with no quick escape in case of emergency. The sheer size of the ship, with its endless hallways and cabins, can also be disorienting, making it easy to get lost or feel trapped. Add in the potential for unexpected storms, mysterious disappearances, or eerie occurrences in the middle of the night, and you have all the elements of a classic thriller on the high seas.