The U.S. Virgin Islands represent a comfortable choice for U.S. citizens vacationing in the Caribbean for the first time. They don't need a passport, the shopping is plentiful and the economy is robust.
Swimming with barracuda can be done in the office or in the Caribbean. They bite in both places, but the barracuda in the Caribbean have much bigger teeth.
Two tours of San Juan spread 10 years apart convince me that the experience is all about timing. The first tour was about places to see. The second was about people to see.