In addition to seeing new wonders, we were able to listen to the volcanic activity using a portable underwater microphone (hydrophone), with the help of our NOAA Vents/Oregon State University colleagues on shore. The hydrophone was placed on the summit of the volcano a safe distance from the eruptive pit. It is the small white cylinder at the base of the marker. Image courtesy of Submarine Ring of Fire 2006 Exploration, NOAA Vents Program.