United States Army Corps of Engineers Lock Performance Monitoring System [website] [open html - 140B]
"The Corps Locks website contains lock and vessel specific information derived from the United States Army Corps of Engineers Lock Performance Monitoring System (LPMS). The information contained here represents a half-hourly updated snapshot of Freedom of Information Act (FOIA) data on U.S. flag vessels and foreign vessels operating in U.S. waterways that transited a Corps-owned or operated lock structure. Detailed information on specific companies or commodities is considered privileged and is not included in the Corps Locks website."
Corps Lock: http://corpslocks.usace.army.mil