Recovery of Moored Sonar Unit (IMAGE) NOAA National Marine Fisheries Service Caption To retrieve the sonar unit, scientists sent an acoustic signal to the unit, causing it to detach from it's mooring and float to the surface. In this photo, crew aboard a chartered fishing vessel retrieve the unit after it surfaced. Credit: NOAA Credit NOAA Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.