George Brkovich, a waterways inspector with the U.S. Army Corps of Engineers Pittsburgh District, prepares a survey boat before heading out on a demonstration using a multibeam sonar on the Allegheny River in Fox Chapel, Pennsylvania, May 7, 2021. The sonar helps provide the district with digital imagery that can detect water depth, erosion or obstructions that may impact navigation on the Pittsburgh rivers. (U.S. Army Corps of Engineers Pittsburgh District photo by Michel Sauret)