Sonardyne International has retrieved its first Pressure Inverted Echo Sounder (PIES) off the coast of Hawaii. This new sensor logging node is designed to accurately measure the average sound velocity through a column of water from the seabed to the sea surface. The information gathered will help oceanographers to better understand the dynamics of the ocean and atmosphere-ocean coupling. On September 24, the Sonardyne PIES was free-fall deployed into a 960-meter deep water channel close to the big island of Hawaii, and commanded to log average sound velocity readings every seven minutes.