One Vogue writer on her snorkeling obsessions—and the best destinations around the world to experience it, for novices and experts alike.

The Mesoamerican Reef stretches 620 miles across Honduras, Guatemala, Belize, and Mexico and is crucial for local communities. Almost two million people depend on it for their livelihoods.

The Mesoamerican Reef, the longest barrier reef in the Western Hemisphere, stretches 1,000 kilometers (620 miles) along the Caribbean coasts of Mexico, Belize, Guatemala and Honduras.

Consisting of two islands, Cayo Grande and Cayo Menor, and 13 smaller cays, Cayos Cochinos is a vital marine protected area of the Mesoamerican Barrier Reef System, also known as the Great Mayan Reef.

Consisting of two islands, Cayo Grande and Cayo Menor, and 13 smaller cays, Cayos Cochinos is a vital marine protected area of the Mesoamerican Barrier Reef System, also known as the Great Mayan Reef.

Consisting of two islands, Cayo Grande and Cayo Menor, and 13 smaller cays, Cayos Cochinos is a vital marine protected area of the Mesoamerican Barrier Reef System, also known as the Great Mayan Reef.

The Mesoamerican Reef (MAR) is the largest barrier reef in the western hemisphere, second only to Australia's Great Barrier Reef in terms of size. Shared by Mexico, Belize, ...