On my Carnival cruises there was a laundry room. They would always have at least two irons tethered to an ironing board. To start the iron, you would twist a kitchen-styled timer. But that was Carnival, not RCCL. I am not sure if the newer RCCL ships have a laundry room.
On my last cruise, I got to thinking, why worry if your clothes are a little wrinkled? THIS IS VACATION!!
!! (not a job interview)