Weeki Wachee Springs State Park in Florida has enchanted visitors since 1947 with underwater performances by "real" mermaids.

Plunging down into the deep, murky waters of a sunken city, divers find themselves transported to an alternate universe cursed by some mysterious apocalypse. The massive roots of an overgrown tree ...

Learn to swim alone with this simple, step-by-step guide. Master techniques in the shallow end, practice kicking, and float ...

Rare footage shows a "Dumbo" octopus swimming near a submersible in the deep ocean. The animal was spotted more than 5,500 feet underwater by a research expedition. The Ocean Exploration Trust's ...

Discover 10 amazing birds that swim as well as—or better than—fish. From penguins to puffins, meet the avian experts of the ...