Mysterious and dangerous to explore, blue holes are underwater caves, formed as long as 300,000 years ago during the Ice Age. They are liquid time capsules, filled with fossils that offer clues to the history of our planet. Introduce blue holes to your students.
Extreme Cave Diving (Video)
Go beneath the surface of the Bahamas in the Caribbean Sea, and explore some of the water-filled caves known as blue holes that stretch for hundreds of miles. (Chapter 2, approx. 12 min.; Program available after broadcast)
Risking It All for Science (Interview)
Hear from the program's producer what drives scientists to delve into flooded caves where they face dangers like rock falls, nitrogen narcosis, and even drowning.