They were rolling in the deep. Scientists have identified what could potentially be the “deepest known blue hole” in the world, extending so far down that the bottom has not yet been reached.

Blue holes are worldwide attractions for amateur and professional divers alike. Here are the world's five best blue holes. Snorklers swimming over Dean´s Blue Hole with a depth of 202 meters on June ...

For people with "thalassophobia," or the fear of deep bodies of water, blue holes are something out of a nightmare. These massive vertical caves open up in the shallow waters near coastlines, but blue ...