We've travelled with some waterproof pads, the width of the twin mattress and maybe 3 feet or so of the length of the bed, and just meet our stateroom host and ask him to use it for making up the bed--and, ahem, also from all the excitement, exhaustion, and yes, the drink station, Dad has included that pad in a couple of middle of the night laundry runs on deck 7, then had a freshly laundered pad for our host when he made up the bed in the morning. I figured I had to do the PJ's anyway. So remember a roll of quarters, some dryer sheets in a ziploc, and the detergent tablets as well. Found it nice to see CM's cleaning and fixing the ship even in the middle of the night like that.