Hi Tss, NO irons are allowed, big fire hazard. Depending on what cruiseline you are one, some of them have self service laundry rooms on the guest decks which have ironing boards and irons. Both Princess and Carnival have them. What ship are you on?
Handheld steamers are okay. Irons are NOT okay on ANY ship. They have self serve laundries on many ships and they often have irons in there attached to the wall for passenger use. The ship also offers cheap pressing of clothes and also if you pack your clothes in those plastic dry cleaning bags they help prevent wrinkles.
We always bring a steam iron travel size and even a table top sized ironing board. My husband cut the fat end of it so it would fit in the suitcase. Princess lines have ironing boards and irons on board. Remember to bring an extension cord!!!
I bring along MY LITTLE STEAMER which is the best clothes steamer I have found. Works great and I got it on ebay. You can get it on HSN, It is made by Joy Mangano.
Hope this helps someone, it takes a 30 seconds to steam up and a minute to do your dress or suit or whatever! I usually unpack right away and steam whatever needs it and hang up so all my stuff is ready to wear.
Have a great cruise.