I say you go for it. If they see it and want it taken done, then do so. Otherwise it's up!! Ok, Kathy now you know, bit of a rebbel (did I spell that right?)here. Could be in trouble with me as a roomie!
I prefer to put a poster on my door that says CRUISE-ADDICT.COM. It is so much easier to find my cabin. If I forget my poster..... I use a ship post card that is given to you in the cabin. I carry my tape stuff with me.
I have seen the ship workers wash the balcony windows once per week during the week. So if you have a banner it will get all wet. You are not supposed to leave anything out on the balcony because it will get wet when they wash the window and the balcony. I saw it in the NCL Cruise ship.
The banner worked great! It hung in there even when we hit the tropical storm outside of Costa Rica. Man our ship was a'rockin'! I knew the Captain from a previous sailing I was on and had no problems hanging the banner whatsoever!
I will post pictures as soon as I've unpacked and found my digital to upload them from.
Song of America Dec '90
Starship Majestic May '89
Sovereign X 5
Majesty Jul '01
Enchantment X 4
Regal Empress Dec '02
Mariner May '07 April '08
Grandeur Feb '08
Inspiration Oct '08
Radiance of the Seas Oct '10