Even Rick Steves, world traveler with just a back pack, said that Jeans are too heavy and warm for the summer months or Caribbean climates. Men and women wear cotton shorts with t-shirts or short sets in the daytime for dining or port excursions. Always wear comfortable shoes either sandals or sneakers. Depending on your port activities, as a rule bring a camera, wear your swim suit if going to a beach or snorkeling, bring a hat and wear your sunglasses and bring your reading glasses and plenty of sunscreen, your ship beach towel if again going to the shore or swimming and a port guide or note book to keep track of where you have been and what you have seen. I put a few dollars, key card and Photo ID if your photo is not embossed on your Sign & Sail card and credit card in an Aqua Safe or fanny pack, with an extra roll of film or two (we take lots of pictures) and sometimes a really cheap rain poncho ($.89 at Walmart) just in case of rain. I don't bring a lot of cash each day just what I think I will need to use. This is where booking a ship's tour helps. You often need more cash for a taxi tour. Hope this helps. If you like to have water to drink, then be sure to bring a sports water bottle filled with ice and ship's tap water with you, too.
Bon Voyage