Roatán Marine Park

Lonely Planet review

Thousands of divers and snorkelers come every year to explore the magnificent reefs just a few yards offshore. Three dive schools operate at the western end where there's excellent snorkeling, though the reef is starting to show damage.

Avoiding contact with the coral is extremely important. Coral has an invisible covering of slime that protects it, much like skin on other animals. Touching the coral can damage this protective covering, exposing it to infection and disease. Large segments of coral can be killed by a single brush of a diver's fin.

Under ideal conditions, most coral grows about 1cm (less than half an inch) per year; even the fastest growing sponges grow only an inch per year. The coral and sponge formations you see in the Bay Islands are the result of centuries of growth. Another good reason not to touch the coral is that it can sting you. Fire coral is the most famous for this - its venomous sting causes a painful burning sensation. Even coral that doesn't sting can be surprisingly sharp or prickly, and cuts from it are notoriously slow to heal.