DETAILS COUNT WHEN BOOKING A SEA CRUISE
|Prinzessin Victoria Luise was the first purpose-built cruise ship.|
Image: Library of Congress, Caption Link: Wikipedia
Unless you are traveling with two staterooms of friends and family never book a room with an adjoining door.
Not only do such doors lack the sound proofing of the bulkheads but if there are thieves aboard they can hear when you are not present and have privacy to work the lock, and usually a simpler lock. The interior bulkheads (walls) of a cruise ship will let sound through but the adjoining stateroom doors hardly block it at all. To avoid getting stuck with an adjoining door stateroom study the deck plan that comes with most cruise brochures. A two sided arrow may indicate such a door, but check the symbol key and discuss this with your booking agent. If you don't want an adjoining door stateroom say so plainly and clearly