Hi hippygurl39, welcome to CruiseReviews! Maybe if you can let us know what you really want to do, we can better assist. Many of us know the islands very well and may be able to save you some money. Picking up on Marsha's reply, I'm thinking you're doing San Juan, St. Thomas and Grand Turk. These are all islands that you can easily do excursions on your own. However, you MUST remember to be back to the ship on time if you are not on a cruise excursion. The ship will NOT wait for anyone that is not on one of their excursions.
Knowing what you really want to do, will help us be able to guide you to how to accomplish your goal! Just be warned, cruising is addictive