These six daredevil dives promise the thrill of a lifetime — from shark encounters in the Caribbean to crocodiles and sea snakes in the Indian and Pacific.

Judy G's photography showcases the marine life you can expect to see underwater on the famed reefs of Mexico's largest Caribbean island, Cozumel.

Scuba divers and snorkelers can study the marine ecosystem in Cuba's Gardens of the Queen aboard the floating classroom M/V Oceans for Youth.

Lionfish use venom as a protective mechanism.

Photojournalist Jill Heinerth surveys the fragile marine habitat in the Arctic, where melting sea ice has an ecosystem hanging in the balance.

Conservation organizations are urging people to stay away from seal pups on the beach.

Scuba divers captured the experience of a lifetime on video when a great white shark visited the group on an Australia dive.