Welcome to cruise-chat. I was initially going to say that I was the wrong person to ask as I am from the northeast, but I see from weather.com that temperatures in Baltimore aren't that far off from ours! Brr. It will probably be a safe bet that you'll need long pants for the first day and last day of the cruise...one pair can serve double duty. My suggestion for tops is to bring clothing that can be layered, which will cut down on packing. Just peel off the layers on the way to the Bahamas, and add them as you return.