Went here many moons ago.  Water was bloody cold with one heck of a draught. Was a small air space above a deep duck - the draught whistled through smacking water into your face as you tried to look through, remember it vividly.  Trip was abandoned as water levels too high.

http://www.hurriyetdailynews.com/discoveries-ongoing-in-turkeys-longest-cave-in-isparta.aspx?pageID=238&nID=87490&NewsCatID=374