Lights from the human-occupied vehicle (HOV) Thetis shine on a hydrothermal vent at about 100 m depth. Samples collected from the vent sites will be analyzed by the science team to gather data which should help explain the natural hydrothermalism south of Milos Island. Image courtesy of Christos Anagnostou, Project PHAEDRA 2006, WHOI, HCMR, Thera Foundation, NOAA.