Several questions:
What is the length of the cruise?
What is the Itinerary?
What cruise line is it?
What kind of activites is the cruise line offering?
What kind of climate will you be in?
You answers will help us help you.
Also, despite the most careful consideration of appropriate clothing, many passengers still find themselves lacking an essential item or two. If this is the case, the boutiques on board can supply most items, including swimwear, t-shirts and sweatshirts, and even formal attire.