All Disney ships will have a pirate night. It's is the only time all dinning place have same menu on the ship. It is not a must but encourage to dress up. you will need to bring your own. My wife and I did dress up as well as a lot of other people. also that i know, Disney is the only ship that does Fireworks on the ship.
also if you stay tune we should be getting a FISH or FE group (not 100% sure the name) going for the cruise... Im still new with Fish groups and how they work, i can only give you an idea what we have done. i tried to look for a form with what a FISH is but could not find it at this time. (will post once i find it) what this is, if you wish to join. is where we put our cabin # last name and # of people with age. example:
Pastor Family
Cabine # 6739
3 people
Mom
Dad
Lilianna (3 years old) anything disney princess
you can put what the little one like if you wish. what will happen is that the people on the list will run around the ship during the cruise dates March 4-11 and give little gifts for the family or individual people (dad and mom = little shots of tequila, Lilianna = Princess bracelet). and when the family gets back from there day out on shore or day from the ship to rest, there is a gift for them. its a nice little surprise when you come back to your room.