Depending on how far you live from the port, you may be sitting in a plane or in a car for several hours. Don a cotton dress, around knee length or longer for a comfortable trip. Lightweight cotton allows your skin to breathe and is versatile, meaning you can go with a solid color or with a funky printed pattern. Bring along a dress to wear on the trip to the boat and on the way back home.
Onboard -- Daytime
Resortwear is the order of the day when it comes to daytime fashion for a cruise ship. Keep it simple but chic with cotton sundresses, spaghetti strap numbers and strapless cover-up styles to wear over your swimsuit. Caftan-style dresses are perfect for lunchtime buffets on the boat and this may be the only time you can actually get away with such an unabashedly casual style in public. Meanwhile, sexy mesh cover-up dresses work over a swimsuit by the pool and can jazz up even the most simple swimsuit look.
Shore excursions mean lots of walking and sightseeing. You will be a visitor so show your respect for the local culture by dressing conservatively. Don't wear a bikini top and shorts into town for shopping, even if you plan to hit the pool later. You can keep the bikini; just cover it with a knee-length or longer dress. Avoid clingy fabrics, like Spandex mixes. If you will be hiking, horseback riding or partaking in other outdoor activities, wear clothes that can handle sweat or water.
Onboard -- Evening
Evening wear is your chance to sparkle and attract attention. Most cruisers -- and cruise staff members -- dress formally or at least semiformally during evenings on the boat. Bring at least one formal dress and two to three semiformal dresses. You can also bring a few cocktail dresses, which are best if you want to hit some of the after-hours spots on the boat after your meal. Slinky jersey fabric won't take up a lot of room in your suitcase, and won't show wrinkles. Make sure you pack the proper undergarments for your special occasion dresses, so you don't have bra strap fashion emergencies.