A birding friend witnessed the same type of illegal hunting a week or so ago, 
on the Potomac River north of the Riverbend Park (VA) visitors center.  I had 
advised seeing  Redhead and a huge raft of Ring-necked Ducks on the river a 
few days earlier, but he observed nothing other than hunters firing from a 
moving boat.

I'm glad to have the phone numbers to call if I observe such conduct in the 
future.

Ralph Wall
Great Falls, VA