2. Cozumel
You can’t beat this Mexican island for its abundant sea-life and remarkable water clarity, regularly reaching visibility levels of 100 to 200 feet. More than 230 species of fish call Cozumel home and the coral diversity is world class. Chankanaab lagoon is an easy-access shallow cove perfect for families or novice snorkelers. The hotels and beach clubs along the Southern shore all offer superb aquarium-like snorkeling right off the beach. At Paradise Reef you might spot the foot-long Splendid Toad Fish found nowhere else on the planet.