A U.S. Army Corps of Engineers Pittsburgh District dive team got a better look at Lock and Dam 4 on the Allegheny River near Natrona by using a barge to break the flow of water heading over the dam. This inventive use of a water vessel reduces the boil or turbulent water that passes over the dam and gives divers a clear look at the dam structure during routine inspections. While the barge can appear to be stuck, it’s actually helping the Corps’ divers move forward in assuring navigable waters for commercial watercraft.