Hi, Paulette!
For 7-night cruises aboard all Disney Cruise Line ships, there are usually two suggested dressier nights for dinner -- one semi-formal and one formal. Formal for men (such as a tuxedo or suit) is requested for gentlemen, and for women, a gown or dress. On the semi-formal night, men can wear a suit or jacket and women a dress or nice pantsuit. Four of your evenings will be cruise casual for dinner meaning no shorts, jeans or t-shirts -- with an additional tropical/pirate party night.
For me and my family, we consider a cruise an extra-special vacation which we plan accordingly. We so rarely get the opportunity to all dress up together that we welcome the chance to take those priceless family photos in fancy duds and breathtaking environments. (Of course, not everyone is
completely happy about dressing up, but they do it to please Mom!) Plus, spending days in the Alaskan wilderness and then coming "home" to a fancy Disney ship just lends itself to an extra special evening experience such as a formal night.
If you're concerned about packing, you can always take a look at
Cruise Line Formal Wear on DisneyCruise.com to have your dressy clothes delivered to you in your stateroom -- saving room in your luggage for other essentials. We always let our fancy clothes do "double duty" by my packing only a little black dress and accessorizing differently each night and by my husband and boys wearing the same pants to dinner for several nights while changing out the shirts.
I hope this helps. Have a wonderful day and a magical vacation. Bon voyage!
Andi