If you are going on an upcoming cruise, it is not necessary for you to max out your credit card to buy outfits and shoes. Your closet is likely to have everything that you will need for the cruise. There are basically three categories of cruise wear which are informal, casual and formal.
The documents along with your cruise package will include a program of the cruise's activities throughout the cruise duration and will indicate how many evenings will fall into the various cruise wear categories. Read the cruise's daily newsletter as the dress code each day will be announced.
Casual wear are clothes you are typically comfortable in wearing. What you plan to do for the day shall indicate your outfit. For cruises during the summer you will typically need your swimwear, a cover-up and sandals. For the time when you will have to go ashore, you can wear a casual tee or tank top (for girls) and a comfortable polo shirt (for guys) paired off with shorts and comfy walking shoes. Learn to mix and match your clothes to save some room in your luggage. If you have plans of shopping for souvenir shirts or you have plans of buying clothes, you can bring less casual clothes.
For evening casual, men are not supposed to wear shorts. This would mean slacks (docker's style) topped off with a nice polo shirt or sports shirt. As for the ladies, this could be a sporty dress, a pants outfit and a skirt and top. The ladies can always jazz up their ensembles with accessories. The first and the last night on board the cruise are usually the nights that allow casual wear. While jeans may be considered casual for some people, some cruise lines discourage their passengers from wearing them in the dining room.
Informal wear can be a bit tricky. This applies to evening events and depending on the particular cruise line could mean different things. For women, it could mean a dressier pants outfit or dress and as the case for men it should include a sports coat. Sometimes it may mean with a tie so it is best to check your cruise documents.
Formal night for women can go from a cocktail dress to elaborate gowns. For gentlemen, they are required to wear a black tie or tuxedo (white dinner jacket or all black) or dark suit.
Comply with your cruise's evening dress codes. It's nice to dress up once in a while.
Source: http://www.therealarticles.com/Article/Understanding-Dress-Codes-Aboard-A-Cruise/149162
