The U.S. Department of State Passport Services Office provides information and services to American citizens about how to obtain, replace or change a passport.

DAN is a 501(c)(3) non-profit medical and research organization dedicated to the safety and health of recreational scuba divers and associated with Duke University Medical Center (DUMC). DAN is supported by the largest association of recreational divers in the world.

The CDC's National Center for Infestious Diseases web site has a ton of health information for travelers, including information on specific diseases, current outbreaks in other countries and recommendations for vaccinations.

Comprehensive updated information about diving and undersea medicine for the non-medical diver, the non-diving medical professional and an excellent reference source for the diving medical specialist.