Video: Freediver Guillaume Nery Journeys into 663-Foot Sinkhole

Those of you who have a fear of open water may not want to watch this video. But if you do, we promise you'll be amazed.

Guillaume Nery is one of the foremost freedivers in the world. Freediving is the practice of diving into water without an oxygen tank -- just holding your breath. Well, Nery decided it would be a splendid idea to do some freediving into Dean's Blue Hole, west of The Bahamas. It seems Dean's Blue Hole is the deepest underwater sinkhole in the world, dropping to a depth of 663 feet.

With his girlfriend working the camera, Nery plunged into the sinkhole, then climbed his way out. Nery told The Huffington Post in an email that he never actually reached the bottom -- it would be impossible to go that far down without oxygen. But over the course of four afternoons, he and his girlfriend captured these mesmerizing pictures. Nery said, "This movie is an artistic project, a fiction."