The underwater world is an oasis for adrenaline junkies. There are few things more exciting than strapping on your oxygen tank, plunging off the side of a dive boat, and sinking into the ocean’s deep blue depths. It's a total rush to swim inside the eye of a school of menacing barracudas or to float by a turtle that is even bigger than you.

To stay safe during your adventure, check out outfits like PADI, (Professional Association of Diving Instructors), the world's largest diver training organization with more 6,000 dive centers. Their PADI Travel Network is a valuable tool that connects divers with PADI Dive Centers and Resorts, dive partners, current course offerings, and deals.

Ready to have an underwater adventure—and get a phenomenal workout while doing it? Check out MensFitness.com's favorite dive sites around the world.