Top-ranked mixed-martial artist Donald Cerrone tells a fascinating true story of a cave dive off the coast of Cozumel. He and his instructor were entering an underwater cave when his instructor lost bouyancy and began to kick up silt from the cave floor, creating utter darkness. Cerrone, in an effort to save his instructor, entered the darkness where he could not see his hands in front of his face and did not know what was up or down, left or right, backwards or forwards.