Remipede

The remipede is a "living fossil" nearly unchanged for 300 million years. It kills its prey, primarily other crustaceans such as cave shrimps, with venom-injecting fangs.

National Geographic Bahamas Blue Holes

Following the guideline her life depends on, a diver threads the needle through a stalagmite forest in Dan's Cave on Abaco Island. A single, misplaced fin kick can shatter mineral formations tens of thousands of years old.

National Geographic Bahamas Blue Holes

Bacteria color the water at a depth of 30 to 36 feet in Sawmill Sink on Abaco. Here and in a colorless layer below, poisonous hydrogen sulfide gas is present. Divers move through it with all deliberate speed.

National Geographic Bahamas Blue Holes

In Stargate, a blue hole on Andros Island, divers illuminate North Passage.

National Geographic Bahamas Blue Holes

"All of a sudden, it's got you," says photographer Wes Skiles of the "insanely dangerous" vortex in Chimney Blue Hole off Grand Bahama. Like a giant bathtub drain, it sucks down millions of gallons when the tide comes in. "It's like going over a waterfall—there's no escape." Keeping his distance, a diver sets up equipment to measure the whirlpool's flow rate.

National Geographic Bahamas Blue Holes

From a protected cove on Long Island, Dean's Blue Hole—Earth's deepest known underwater cave—plunges more than 600 feet into darkness.

National Geographic Bahamas Blue Holes

The Cascade Room, some 80 feet beneath the surface, leads divers deeper into Dan's Cave on Abaco Island. Nearly seven miles of the cave have been explored since the mid-1990s.