The Keys have the third longest barrier reef in the world, and the only tropical coral reefs in the contiguous United States. The best of the snorkeling and scuba diving is offshore on the coral reefs. Additionally, there are also many wrecks to dive. There are opportunities for snorkeling from shore in several areas, but do not compare to getting out on the reef! Snorkeling and dive charters are readily available throughout the keys. Sombrero Light Key, and Looe Key are two exceptional protected sites with many patch reefs in between.