Located off Australia's east coast, the Great Barrier Reef is the world's largest, youngest, most famous, and most biodiverse aquatic ecosystem to be found anywhere on the planet. Comprising over 2,500 individual reefs, the World Wildlife Fund says it is home to over 1,500 species of fish, 30 species of marine mammals, and six species of turtles.

1. Great Barrier Reef, Australia

In Raja Ampat, Indonesia, snorkelers can spend years floating along the pristine coral reefs, and only see a fraction of what these bountiful waters provide. Per the Raja Ampat Biodiversity Nature Resort, the protected waters are home to over 1,700 fish species, 700 varieties of mollusks, about 30 marine mammals, and nearly 80% of the planet's coral species.

2. Raja Ampat, Indonesia

Known for its biological diversity and evolution unhindered by the influences of humankind, the Galapagos Islands is a chain of 19 volcanic islands located approximately 600 miles from continental Ecuador. Great for all skill levels, many of its best snorkeling spots can be accessed from nearby beaches.

3. Galapagos Islands, Ecuador

Komodo National Park, Indonesia, is home to daily tidal flows that offer some of the world's most pristine conditions for aquatic life and some of the country's most abundant marine ecosystems. The waters surrounding the island are crystal clear, allowing for unhindered visibility to the colorful habitats only a few feet below the water's surface.

A majestic volcanic island surrounded by a crystal clear azure lagoon and vibrant coral reefs, Bora Bora in French Polynesia has calm, warm waters year-round, providing optimal snorkeling conditions for swimmers of all skill levels. Per the Bora Bora Island Guide, many of the region's best snorkeling hot spots can be reached directly from the island's coastline.

5. Bora Bora, French Polynesia