US Dollar is used on all the Caribbean Islands. No need to exchange money at all. The US Virgin Islands are part of the United States so the currency is US Dollars there anyway. Even on the Islands that arent part of the US, and have thir own currency, the dollar is what they want you to use and it is gladly accepted. They even have Burger King, Kentucky Fried Chicken, McDonalds and Pizza Hut just in case you get home sick.