US External Territories — Visas and Vaccinations
US citizens are not required to obtain a visa in order to visit any of the US External Territories, nor do they need a passport to travel here. As with other domestic destinations within the US, travel using a driver’s license or another form of photographic ID is sufficient. For some destinations, you will be required to obtain an ESTA travel authority, even as an American citizen. The process is entirely electronic; the application is made online by visiting the following website: https://esta.cbp.dhs.gov/. You will need to apply for ESTA authorization at least 24 hours before travel.
Citizens of other nations will need to go through the same visa requirements as if visiting the US. Citizens of Canada, the UK and other EU member states, Australia, and New Zealand are visa exempt, although they need to go through the process of obtaining an ESTA travel authority by applying online at least 24 hours prior to travel. On being granted the ESTA, you are permitted a stay of up to 90 days in the US External Territories for tourist purposes. For some places, such as American Samoa, you will only be granted 30 days initially, although this can be extended. You will also require a current passport with six months’ validity.
Health and Safety
Public health across all of the US External Territories is generally very good since the territories adopt standards found in the mainland US. However, you should always travel with full health insurance coverage in case of any necessary hospital treatment. There is no prevalence of malaria or yellow fever in the US External Territories. There is a slight risk of dengue fever so every care should be taken to defend against insect bites by covering up exposed skin and by applying insect repellent. In Guam, you also need to be cautious of contracting Japanese encephalitis.
Since most of the US External Territories fall within the tropical zone, you should ensure the following routine vaccinations are up to date before you travel here: hepatitis A and B, rabies, tetanus, tuberculosis, and typhoid. If these immunizations are not current, you should seek them at least six weeks before travel.
Crime levels are extremely low in the US External Territories of American Samoa, Guam, and US Virgin Islands, although Puerto Rico sees higher levels of crime. The main problem that tourists face is theft. You should always take care of your belongings and be especially vigilant when walking around at night, particularly if you are alone. Mostly theft occurs in the big cities of San Juan and Ponce, although car theft is also an issue, so be vigilant of your belongings and be careful where you park your car. In any case, you should avoid public housing complexes known as caserios and shanty town slums where the prevalence of dangerous crime is higher.
Since many of the US External Territories are located in the tropical zone, many of the islands are at risk of hurricanes or tropical cyclones at various times of the year. The periods vary depending on which country you are visiting. You can seek weather warnings by visiting the American National Hurricane Center.